:root {
    --color-page-bg: #f4f6fb;
    --color-surface: #ffffff;
    --color-surface-soft: #f8fafc;
    --color-border: #d8e0f0;
    --color-border-strong: #c0c9dc;
    --color-text: #1f2937;
    --color-text-muted: #64748b;
    --color-primary: #2563eb;
    --color-primary-soft: #dbeafe;
    --color-primary-strong: #1d4ed8;
    --color-success: #059669;
    --color-warning: #f59e0b;
    --color-danger: #dc2626;
    --color-glow: rgba(245, 158, 11, 0.28);
    --color-shadow: rgba(15, 23, 42, 0.08);
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", sans-serif;
    --font-mono: "JetBrains Mono", "SFMono-Regular", Menlo, Consolas, monospace;
    /* Optimized layout: compress left columns, expand Program column */
    --layout-max-width: 1220px;
    --header-row-height: 130px;
    --ui-scale: 1;
    /* New column widths: 250-250-250-380 for better Program space */
    --layout-columns: 250px 250px 250px 380px;
    --layout-rows: 130px 560px;
}

.app-toast {
    display: inline-block;
    min-width: 120px;
    max-width: 320px;
    word-break: break-word;
}

.app-toast-error {
    background: #ef4444; /* red */
}

.app-toast-warning {
    background: #f59e0b; /* amber */
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

.hidden {
    display: none !important;
}

/* Progressive content reveal animation */
.content-line {
    opacity: 0;
    transform: translateY(10px);
    transition: opacity 0.4s ease, transform 0.4s ease;
}

.content-line.hidden {
    display: none;
}

.content-line.fade-in {
    opacity: 1;
    transform: translateY(0);
}

/* Tutorial pulse animation for "Next" button */
@keyframes pulse {
    0%, 100% {
        transform: scale(1);
        box-shadow: 0 0 0 0 rgba(245, 158, 11, 0.7);
    }
    50% {
        transform: scale(1.05);
        box-shadow: 0 0 20px 10px rgba(245, 158, 11, 0);
    }
}

.pulse-animation {
    animation: pulse 1.5s ease-in-out infinite;
}

body {
    font-family: var(--font-sans);
    min-height: 100vh;
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* 只对实验任务页面隐藏滚动条 */
body:has(#experimentContent) {
    overflow: hidden;
}

/* Magic Stones inspired page styles */
.light-page, .dark-page {
    margin: 0;
    padding: 2rem 0; /* 添加垂直padding以便内容不会贴边 */
    width: 100vw;
    min-height: 100vh; /* 改为 min-height 允许内容超出时滚动 */
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    overflow-y: auto; /* 允许垂直滚动 */
}

.light-page {
    background-color: #f4f4f4;
    color: #4c4c4c;
}

.dark-page {
    background-color: #0b0c10;
    color: #c5c6c7;
}

.light-page h1 {
    color: #000;
}

.dark-page h1 {
    color: #fff;
}

/* Frame and instruction boxes */
.frame {
    background: #fff;
    padding: 2em 3em;
    border-radius: 8px;
    margin: 2em 0;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

/* Instruction page container */
.instruction-page {
    width: 1000px;
    min-width: 1000px;
    max-width: 1000px;
    padding: 0 2rem;
}

.instruction-page h1 {
    margin-bottom: 1.5rem;
}

/* Welcome section outside the instruction box */
#welcome-section {
    width: 1000px;
    text-align: left;
    margin: 1.5rem 0;
}

#welcome-section h2 {
    color: #1f2937;
    font-size: 2rem;
    font-weight: 700;
    margin: 0;
}

.instruction {
    background-color: #1f2937;
    border-radius: 8px;
    padding: 2em 3em;
    margin: 2em 0;
    font-size: 1.05rem;
    color: #c5c6c7;
    width: 1000px;
    min-width: 1000px;
    max-width: 1000px;
}

.light-page .instruction {
    background: #fff;
    color: #1f2937;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.instruction h2 {
    color: #fff;
    margin-top: 0;
    margin-bottom: 1.5rem;
}

.light-page .instruction h2 {
    color: #1f2937;
}

.instruction h3 {
    color: #fbbf24;
    margin-top: 2rem;
    margin-bottom: 1rem;
}

.light-page .instruction h3 {
    color: #d97706;
}

.instruction ul {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

.instruction ol {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

.instruction li {
    margin-bottom: 0.85rem;
    line-height: 1.7;
}

.instruction p {
    line-height: 1.75;
    margin-bottom: 1rem;
}

.instruction .content-line {
    margin-bottom: 0.5rem;
}

.instruction .content-line h3 {
    margin-top: 2.5rem;
    margin-bottom: 1.2rem;
}

.instruction .content-line:first-child h3 {
    margin-top: 1.5rem;
}

/* Button group */
.button-group {
    display: flex;
    flex-direction: row;
    justify-content: center;
    align-items: center;
    margin: 2rem 0;
}

.big-button {
    background-color: #2563eb;
    font-size: 1.25rem;
    padding: 0.85rem 3rem;
    color: #fff;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    font-weight: 600;
    transition: background 0.2s ease;
}

.big-button:hover {
    background-color: #1d4ed8;
}

.big-button:disabled {
    background-color: #9ca3af;
    cursor: not-allowed;
}

/* Consent page styles */
#landing {
    width: 900px;
    min-width: 900px;
    max-width: 900px;
    padding: 0 2rem;
}

#landing h1 {
    margin-bottom: 1.5rem;
}

#landing .frame {
    width: 900px;
    min-width: 900px;
    max-width: 900px;
}

/* Scrollable consent info */
#consent-info {
    height: 450px;
    overflow-y: scroll;
    padding: 0 1rem;
    margin-bottom: 1.5rem;
}

#consent-info::-webkit-scrollbar {
    width: 8px;
}

#consent-info::-webkit-scrollbar-track {
    background: #f1f1f1;
    border-radius: 4px;
}

#consent-info::-webkit-scrollbar-thumb {
    background: #888;
    border-radius: 4px;
}

#consent-info::-webkit-scrollbar-thumb:hover {
    background: #555;
}

#consent-info h3 {
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-text);
}

#consent-info ul, #consent-info ol {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

#consent-info li {
    margin-bottom: 0.5rem;
    line-height: 1.6;
}

#consent-info p {
    line-height: 1.7;
    margin-bottom: 1rem;
}

#consent-info p strong {
    margin-top: 1.2rem;
    display: inline-block;
}

#consent-info a {
    color: #2563eb;
    text-decoration: none;
}

#consent-info a:hover {
    text-decoration: underline;
}

/* Reminder page styles */
#reminder {
    width: 800px;
    min-width: 800px;
    max-width: 800px;
    padding: 0 2rem;
}

#reminder h1 {
    margin-bottom: 1.5rem;
}

#reminder .frame {
    width: 800px;
    min-width: 800px;
    max-width: 800px;
}

#reminder .frame p {
    line-height: 1.8;
    margin-bottom: 1rem;
    font-size: 1.05rem;
}

#reminder .frame ul {
    margin-top: 1rem;
    margin-left: 1.5rem;
}

#reminder .frame li {
    margin-bottom: 1rem;
    line-height: 1.7;
    font-size: 1.05rem;
}

/* Comprehension page styles */
#comprehension {
    width: 900px;
    min-width: 900px;
    max-width: 900px;
    padding: 0 2rem;
}

#comprehension h1 {
    margin-bottom: 1.5rem;
}

#comprehension .frame {
    padding: 2.5em 3.5em;
    width: 900px;
    min-width: 900px;
    max-width: 900px;
}

#comprehension form ol {
    counter-reset: question-counter;
    list-style: none;
    padding-left: 0;
}

#comprehension form ol > li {
    counter-increment: question-counter;
    margin-bottom: 0.3rem;
    font-weight: 600;
    font-size: 1.05rem;
    line-height: 1.4;
}

#comprehension form ol > li::before {
    content: counter(question-counter) ". ";
}

#comprehension form p {
    margin-top: 0;
    margin-bottom: 2rem;
    padding-left: 1.5rem;
    font-weight: normal;
    line-height: 2.2;
    font-size: 1rem;
}

#comprehension form input[type="radio"] {
    margin-right: 0.6rem;
    margin-bottom: 0;
    vertical-align: middle;
}

#comprehension form p br {
    display: block;
    content: "";
    margin-top: 0.4rem;
}

/* Task page styles */
body:has(#experimentContent) {
    background: var(--color-page-bg);
    padding: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.randomize-option input[type="checkbox"] {
    width: 20px;
    height: 20px;
    margin-right: 0.8rem;
    cursor: pointer;
}

.start-btn {
    border: none;
    border-radius: 0;
    padding: 0.95rem 2.8rem;
    background: var(--color-primary);
    color: white;
    font-size: 1.15rem;
    font-weight: 600;
    cursor: pointer;
    transition: background 0.2s ease;
    box-shadow: none;
}

.start-btn:hover {
    background: #1d4ed8;
}

/* ------------------------------------------------------------------
   Global layout and progress
------------------------------------------------------------------- */

.progress-bar {
    background: #1f2937;
    color: white;
    padding: 0.5rem 1.2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1.2rem;
    box-shadow: none;
    width: 1200px;
    min-width: 1200px;
    max-width: 1200px;
    margin: 0 auto;
    min-height: 45px;
    max-height: 45px;
    flex-shrink: 0;
}

.progress-info {
    font-weight: 600;
    font-size: 0.9rem;
    letter-spacing: 0.02em;
    white-space: nowrap;
}

.progress-track {
    flex: 1;
    max-width: 600px;
    height: 8px;
    border-radius: 0;
    background: rgba(255, 255, 255, 0.18);
    overflow: hidden;
}

.progress-fill {
    height: 100%;
    background: var(--color-primary);
    transition: width 0.3s ease;
}

#experimentContent {
    width: 1200px;
    min-width: 1200px;
    max-width: 1200px;
    height: 750px; /* 固定高度：进度条45px + 内容区域705px */
    min-height: 750px;
    max-height: 750px;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 0.6rem;
    margin: 0 auto;
    transform-origin: center center;
    /* 缩放将通过 JavaScript 动态计算 */
}

.content-area {
    display: grid;
    /* 固定4列布局，总宽度1200px（270+270+210+380 + 间隙） */
    grid-template-columns: 270px 270px 210px 380px;
    /* 固定行高：头部125px + 主内容565px */
    grid-template-rows: 125px 565px;
    /* 保持4列布局 */
    grid-template-areas:
        "points preview controls program"
        "target workspace controls program";
    width: 1200px;
    min-width: 1200px;
    max-width: 1200px;
    height: 700px;
    padding: 0.85rem;
    box-sizing: border-box;
    gap: 0.85rem;
    margin: 0 auto;
    flex: 1;
}

.panel-card {
    background: var(--color-surface);
    border-radius: 0;
    padding: 0.65rem;
    box-shadow: none;
    border: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    position: relative;
    min-height: 0;
    height: 100%;
    max-height: 100%;
    overflow: hidden;
}

.target-card { 
    grid-area: target;
    padding: 0.9rem 0.9rem 1rem;
    display: flex;
    flex-direction: column;
}
.pattern-card { 
    grid-area: workspace;
    padding: 0.9rem 0.9rem 1rem;
    display: flex;
    flex-direction: column;
}
.program-card { grid-area: program; }
.controls-card { 
    grid-area: controls;
    padding: 0.85rem;
}
.preview-card { grid-area: preview; }
.points-card {
    grid-area: points;
    background: #ffffff;
    border-radius: 0;
    box-shadow: none;
    border: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    height: 100%;
    padding: 0.75rem;
    color: #0f172a;
    text-align: center;
    width: 100%;
    justify-self: start;
}
.points-label {
    font-size: 0.9rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.12em;
}
.points-value {
    margin-top: 0.6rem;
    font-size: 2.8rem;
    font-weight: 800;
    line-height: 1;
    font-family: var(--font-mono);
}

.panel-card.target-card,
.panel-card.pattern-card {
    align-items: stretch;
    justify-content: flex-start;
}

.panel-title,
.panel-subtitle {
    font-weight: 700;
    color: var(--color-text);
    letter-spacing: 0.02em;
}

.panel-title {
    font-size: 0.85rem;
    margin-bottom: 0.55rem;
}

.panel-subtitle {
    font-size: 0.75rem;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    color: #334155;
    letter-spacing: 0.08em;
}

.pattern-view,
.workspace-canvas {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    background: #ffffff;
    border-radius: 0;
    border: 1px solid var(--color-border);
    padding: 0.6rem;
    min-height: 200px;
}

.workspace-canvas svg,
.pattern-view svg {
    max-width: 100%;
    max-height: 100%;
    width: 170px;
    height: 170px;
    object-fit: contain;
}

/* Program panel --------------------------------------------------- */

.program-card {
    padding: 0.65rem 0.65rem 0.85rem; /* give a bit more space at the bottom */
    display: flex;
    flex-direction: column;
    gap: 0.6rem;
    min-width: 0;
    max-height: 100%;
    overflow: hidden;
}

.program-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 0.6rem;
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--color-border);
    flex-shrink: 0;
}

.program-header h3 {
    margin-right: auto;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    color: #334155;
    letter-spacing: 0.08em;
}

.operations-log {
    flex: 1;
    overflow-y: auto;
    overflow-x: hidden;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    padding-right: 0.3rem;
    padding-bottom: 0.5rem; /* extra breathing room at bottom */
    min-height: 0;
    scroll-behavior: smooth;
}

.operations-log::-webkit-scrollbar {
    width: 6px;
}

.operations-log::-webkit-scrollbar-track {
    background: var(--color-surface-soft);
    border-radius: 0;
}

.operations-log::-webkit-scrollbar-thumb {
    background: var(--color-border-strong);
    border-radius: 0;
}

.operations-log::-webkit-scrollbar-thumb:hover {
    background: var(--color-primary);
}

.operation-thumb {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.45rem 2.2rem 0.45rem 0.5rem;
    border-radius: 0;
    border: 1px solid rgba(148, 163, 184, 0.4);
    background: #ffffff;
    cursor: pointer;
    position: relative;
    transition: background 0.15s ease, border-color 0.15s ease;
    min-width: 0;
}

.operation-thumb:hover {
    background: #f1f5f9;
    border-color: rgba(99, 102, 241, 0.4);
}

.operation-thumb.selected {
    border-color: #2563eb;
    background: #e0e7ff;
}

/* Favorites add button shows on hover to reduce clutter */
.operation-thumb .favorite-add-btn,
.operation-thumb .favorite-badge {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    right: 8px;
    z-index: 2;
}

.operation-thumb .favorite-add-btn {
    width: 26px;
    height: 26px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    border: none;
    background: transparent;
    color: #d97706;
    font-weight: 700;
    font-size: 1.2rem;
    cursor: pointer;
    transition: all 0.15s ease;
}

.operation-thumb .favorite-add-btn:hover {
    background: #fff7ed;
    color: #b45309;
    transform: translateY(-50%) scale(1.2);
}

.operation-thumb .favorite-badge {
    color: #b45309;
    font-weight: 700;
    font-size: 1rem;
}

.operation-thumb.newly-added-binary {
    border-color: #7c3aed;
    background: #ede9fe;
}

.operation-thumb.newly-added-primitive {
    border-color: #2563eb;
    background: #e0f2fe;
}

.operation-thumb.newly-added-transform {
    border-color: #059669;
    background: #d1fae5;
}

.selection-badge {
    position: absolute;
    top: 0.35rem;
    right: 0.35rem;
    width: 1.25rem;
    height: 1.25rem;
    border-radius: 9999px;
    background: #f97316;
    color: white;
    font-weight: 600;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: none;
    font-size: 0.7rem;
}

.line-number {
    flex-shrink: 0;
    width: 1.5rem;
    height: 1.5rem;
    border-radius: 9999px;
    background: rgba(226, 232, 240, 0.8);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 600;
    color: #1e293b;
    font-size: 0.75rem;
}

.thumb-svg {
    flex-shrink: 0;
    width: 44px;
    height: 44px;
    border-radius: 0;
    overflow: hidden;
    background: white;
    box-shadow: inset 0 0 0 1px rgba(148, 163, 184, 0.35);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 3px; /* increased padding to prevent edge clipping */
}

.thumb-svg svg {
    width: 28px;
    height: 28px;
}

.thumb-label {
    flex: 1;
    min-width: 0;
    font-size: 0.82rem;
    font-weight: 600;
    color: var(--color-text-muted);
    display: flex;
    align-items: center;
    gap: 0.35rem;
    overflow: hidden;
}

.program-expr {
    display: inline-flex;
    align-items: center;
    flex-wrap: nowrap;
    gap: 0.3rem;
    font-family: var(--font-mono);
    font-size: 0.78rem;
    background: transparent;
    padding: 0;
    border-radius: 0;
    white-space: nowrap;
    max-width: 100%;
    overflow: visible; /* changed to visible to prevent icon clipping */
}

.program-expr-op,
.program-expr-comma,
.program-expr-close {
    color: #c2410c;
    font-weight: 600;
    flex-shrink: 0;
}

.program-expr-thumb {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: var(--binary-operand-size, 62px);
    height: var(--binary-operand-size, 62px);
    border-radius: 0;
    background: #ffffff;
    border: 1px solid #cbd5e1;
    padding: 0;
    flex-shrink: 0;
}

.program-expr-thumb svg {
    width: 100%;
    height: 100%;
}

.program-expr-label {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    color: #475569;
    opacity: 0.75;
    display: inline-flex;
    align-items: center;
}

/* Controls -------------------------------------------------------- */

.controls-card {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    overflow: visible;
    min-height: 0;
}

.controls-section {
    display: flex;
    flex-direction: column;
    gap: 0.55rem;
    flex-shrink: 0;
}

.helpers-section {
    flex: 1 1 auto;
    min-height: 0;
}

/* Sub-panels inside controls to match mockup cards */
.section-panel {
    background: transparent;
    border: none;
    border-radius: 0;
    padding: 0;
}

.controls-section + .controls-section {
    padding-top: 0.65rem;
    margin-top: 0.65rem;
    border-top: 1px dashed rgba(148, 163, 184, 0.3);
}

.controls-section .panel-subtitle {
    margin-bottom: 0.45rem;
}

.preview-card {
    gap: 0.6rem;
    background: #ffffff;
    border: 1px solid #d1d5e3;
    /* Align with Controls column */
    justify-self: stretch;
    max-width: 250px;
    width: 250px;
    height: auto;
    min-height: var(--header-row-height);
    max-height: 180px;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    justify-content: flex-start;
    padding: 0.6rem;
}

.operations-grid {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0.45rem;
}

.primitives-grid-inline {
    display: grid;
    grid-template-columns: repeat(3, minmax(56px, 1fr));
    gap: 0.45rem;
    padding: 0.45rem;
    border-radius: 0;
    background: transparent;
    border: none;
    min-height: 0;
    flex: 1 1 auto;
    max-height: 360px; /* allow many items with scroll */
    min-height: 120px;
    overflow-y: auto;
    overflow-x: hidden;
    justify-items: center;
    justify-content: center;
}

.helpers-panel { 
    background: #eef2ff; 
    border-color: rgba(148,163,184,0.45);
    padding: 0.55rem;
    border-radius: 0;
    border: 1px solid rgba(148, 163, 184, 0.35);
    max-height: 420px;
    overflow-y: auto;
    overflow-x: hidden;
}

.helpers-panel::-webkit-scrollbar {
    width: 6px;
}

.helpers-panel::-webkit-scrollbar-thumb {
    background: rgba(148, 163, 184, 0.55);
    border-radius: 0;
}

.helpers-grid::-webkit-scrollbar {
    width: 6px;
}

.helpers-grid::-webkit-scrollbar-thumb {
    background: rgba(148, 163, 184, 0.55);
    border-radius: 0;
}

.helpers-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: flex-start;
}

.helpers-empty {
    font-size: 0.95rem;
    color: var(--color-text-muted);
    text-align: left;
    padding: 0.4rem 0.2rem;
}

/* Helper item with delete button for freeplay */
.helper-item {
    position: relative;
    display: inline-block;
}

.helper-delete {
    position: absolute;
    top: -4px;
    right: -4px;
    width: 18px;
    height: 18px;
    border-radius: 50%;
    background: #ef4444;
    color: white;
    border: none;
    cursor: pointer;
    font-size: 14px;
    line-height: 1;
    padding: 0;
    z-index: 10;
    opacity: 1; /* 改为一直显示 */
    transition: opacity 0.2s;
}

.helper-item:hover .helper-delete {
    opacity: 1;
    transform: scale(1.1); /* 悬停时稍微放大 */
}

.helpers-section .panel-subtitle {
    font-size: 0.82rem;
    font-weight: 700;
    text-transform: uppercase;
    color: #334155;
    letter-spacing: 0.08em;
    margin-bottom: 0.6rem;
}

.helpers-title {
    font-size: 0.82rem;
    font-weight: 700;
    text-transform: uppercase;
    color: #334155;
    letter-spacing: 0.08em;
    margin: 0 0 0.6rem 0;
}

.btn,
.transform-btn,
.binary-btn,
.primitive-btn {
    border: 1px solid #cbd5e1;
    border-radius: 0;
    padding: 0.4rem 0.6rem;
    background: #f8fafc;
    color: #1f2937;
    font-size: 0.72rem;
    font-weight: 500;
    text-transform: none;
    letter-spacing: 0;
    cursor: pointer;
    transition: background 0.15s ease, border-color 0.15s ease;
    box-shadow: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.25rem;
    min-height: 38px;
}

.btn:hover,
.transform-btn:hover,
.binary-btn:hover,
.primitive-btn:hover {
    background: #e2e8f0;
    border-color: #a8b4c6;
}

.binary-btn {
    background: #eef2ff;
    color: #1d4ed8;
}

.binary-btn.selected,
.unary-btn.selected {
    background: #1d4ed8;
    color: #ffffff;
    border-color: #1d4ed8;
}

/* Make unary buttons share the same base appearance as binary buttons */
.unary-btn {
    background: #eef2ff;
    color: #1d4ed8;
}

.binary-btn.disabled,
.transform-btn.disabled,
.primitive-btn.disabled,
.btn:disabled {
    opacity: 0.4;
    cursor: not-allowed !important;
    transform: none !important;
    box-shadow: none !important;
}

.primitive-btn {
    min-height: 54px;
    border-radius: 0;
    background: #f8fafc;
    border-color: #cbd5e1;
    padding: 0.5rem;
}

.primitive-btn svg {
    width: 36px;
    height: 36px;
}

.primitive-btn.selected {
    border-color: #1d4ed8;
    background: #e0e7ff;
}

.transform-btn.selected,
.binary-btn.selected {
    border-color: #1d4ed8;
    box-shadow: none;
}

.primitive-btn.binary-selected {
    border: 2px solid #b45309;
    background: #fff7ed;
    box-shadow: none;
    animation: none;
}

.btn-primary {
    background: #1d4ed8;
    color: white;
    border-color: #1d4ed8;
}

.btn-success,
.binary-confirm-btn {
    background: #0f766e;
    color: white;
    border-color: #0f766e;
    box-shadow: none;
}

.btn-warning,
.binary-cancel-btn {
    background: #b45309;
    color: white;
    border-color: #b45309;
    box-shadow: none;
}

/* Binary preview inline panel ------------------------------------ */

.preview-card .panel-title {
    font-size: 0.9rem;
    margin-bottom: 0.4rem;
    font-weight: 700;
}

.binary-preview-panel {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    animation: slideDown 0.25s ease-out;
    flex: 1;
    min-height: 0;
}

.binary-preview-header {
    /* Hide header to avoid layout jumping when entering operations */
    display: none !important;
}

.binary-preview-header::before {
    content: "⚡";
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 1.75rem;
    height: 1.75rem;
    border-radius: 0;
    background: rgba(249, 115, 22, 0.18);
}

.binary-preview-title {
    font-size: 0.95rem;
    line-height: 1.45;
}

.binary-preview-placeholder { display: none; }

.binary-preview-body {
    --binary-operand-size: 60px;
    display: flex;
    align-items: stretch;
    flex-wrap: nowrap;
    justify-content: center;
    gap: 0.5rem;
    padding: 0;
    border: none;
    border-radius: 0;
    background: transparent;
    box-shadow: none;
    /* center preview content */
    margin: 0 auto;
    flex: 1;
    min-height: 0;
}

/* Compact the preview content so it fits in the 120px header row */
.preview-card .binary-preview-body {
    --binary-operand-size: 52px; /* enough space for complete icon */
    padding: 0;
    align-items: center;
    gap: 0.3rem;
}

.binary-inline-op,
.binary-inline-comma,
.binary-inline-close {
    font-family: var(--font-mono);
    font-weight: 600;
    font-size: 0.7rem;
    color: #475569;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: var(--binary-operand-size);
    padding: 0 0.2rem;
    line-height: 1;
}

.binary-inline-op,
.binary-inline-comma,
.binary-inline-close {
    color: #c2410c;
}

.operand-box {
    width: var(--binary-operand-size, 62px);
    height: var(--binary-operand-size, 62px);
    border-radius: 0;
    border: 1px solid #cbd5e1;
    background: #ffffff;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    cursor: pointer;
    transition: border-color 0.15s ease;
    padding: 0;
}

.operand-box svg {
    width: 100% !important;
    height: 100% !important;
    display: block;
}

.preview-card .operand-box svg {
    width: 100% !important;
    height: 100% !important;
}

/* Make program expression operands reuse preview icon sizing */
.program-card .program-expr .operand-box {
    --binary-operand-size: 52px;
}
.program-card .program-expr .operand-box svg {
    width: 100% !important;
    height: 100% !important;
}

/* Step result thumbnail in Your Program: match preview sizing */
.program-card .operation-thumb > .operand-box.program-result {
    --binary-operand-size: 52px;
    margin-right: 0.2rem;
}
.program-card .operation-thumb > .operand-box.program-result svg {
    width: 100% !important;
    height: 100% !important;
}

.operand-box:not(:empty) {
    border-color: #1d4ed8;
    background: #ffffff;
}

.operand-box:empty::before {
    content: "operand";
    text-transform: none;
    font-size: 0.7rem;
    letter-spacing: 0.04em;
    color: #64748b;
    font-weight: 500;
}

#binaryOperandA:empty::before { content: "operand a"; }
#binaryOperandB:empty::before { content: "operand b"; }

/* Pulse highlight on operand boxes when filled from favorites */
.operand-pulse-a { animation: operandPulseA 650ms ease-out; }
.operand-pulse-b { animation: operandPulseB 650ms ease-out; }
.operand-pulse-u { animation: operandPulseU 650ms ease-out; }

.binary-preview-footer {
    margin-top: auto;
    padding-top: 0;
    border-top: none;
    display: flex;
    justify-content: center;
    gap: 0.4rem;
    flex-shrink: 0;
}

.preview-card .binary-preview-footer {
    margin-top: 0.3rem;
}

.binary-preview-footer .btn {
    min-width: 86px;
    justify-content: center;
    padding: 0.35rem 0.5rem;
    font-size: 0.7rem;
    min-height: 28px;
}

#workspace.preview-glow {
    box-shadow: none;
    outline: 2px solid #f59e0b;
    outline-offset: -4px;
}


/* Feedback & completion modals ----------------------------------- */

.feedback-modal,
.completion-modal {
    position: fixed;
    inset: 0;
    display: none;
    align-items: center;
    justify-content: center;
    background: rgba(15, 23, 42, 0.55);
    backdrop-filter: blur(2px);
    z-index: 1500;
    animation: fadeIn 0.25s ease-out;
}

.feedback-modal.show,
.completion-modal.show,
.completion-modal[style*="display: flex"],
.feedback-modal[style*="display: flex"] {
    display: flex !important;
}

.feedback-content,
.modal-content {
    background: var(--color-surface);
    border-radius: 0;
    padding: 2.5rem 3rem;
    text-align: center;
    box-shadow: none;
    border: 1px solid rgba(148, 163, 184, 0.4);
    max-width: 460px;
    animation: slideUp 0.3s ease-out;
}

.feedback-icon {
    font-size: 3.2rem;
    margin-bottom: 0.75rem;
}

.feedback-icon.success { color: var(--color-success); }
.feedback-icon.error { color: var(--color-danger); }

.feedback-message {
    font-size: 1.4rem;
    font-weight: 700;
    color: var(--color-text);
    line-height: 1.45;
}

.modal-content h2 {
    font-size: 1.8rem;
    margin-bottom: 0.75rem;
}

.modal-content p {
    color: var(--color-text-muted);
    margin-bottom: 1.5rem;
}

.completion-points {
    color: var(--color-primary-strong);
    font-weight: 700;
    font-size: 1.15rem;
}

/* Free Play Completion Modal Styles */
.modal {
    position: fixed;
    inset: 0;
    display: none;
    align-items: center;
    justify-content: center;
    background: rgba(15, 23, 42, 0.85);
    backdrop-filter: blur(8px);
    z-index: 2000;
    animation: fadeIn 0.2s ease-out;
}

.completion-container {
    width: 100%;
}

.completion-header {
    text-align: center;
}

.completion-header h2 {
    font-size: 1.75rem;
    margin-bottom: 0.5rem;
}

.completion-subtitle {
    font-size: 1rem;
}

.completion-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
    margin-bottom: 2rem;
    padding: 1.5rem;
    background: rgba(30, 41, 59, 0.5);
    border-radius: 8px;
}

.stat-item {
    text-align: center;
}

.stat-label {
    display: block;
    font-size: 0.85rem;
    color: #94a3b8;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 0.5rem;
}

.stat-value {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: #3b82f6;
}

.completion-actions {
    margin: 2rem 0;
    text-align: center;
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.1rem;
}

.completion-note {
    text-align: center;
    color: #94a3b8;
    font-size: 0.95rem;
    margin-top: 1.5rem;
}

.completion-contact {
    text-align: center;
    color: #cbd5e1;
    font-size: 0.9rem;
    margin-top: 0.75rem;
    padding: 1rem;
    background: rgba(30, 41, 59, 0.3);
    border-radius: 6px;
}

.completion-contact strong {
    color: #3b82f6;
    font-weight: 600;
}

/* Utility animations ---------------------------------------------- */

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from { transform: translateY(20px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

@keyframes slideDown {
    from { transform: translateY(-10px); opacity: 0; }
    to { transform: translateY(0); opacity: 1; }
}

@keyframes operandPulseA {
    0% { box-shadow: 0 0 0 0 rgba(37,99,235,0.0), 0 14px 32px rgba(37,99,235,0.0); }
    35% { box-shadow: 0 0 0 8px rgba(37,99,235,0.18), 0 14px 32px rgba(37,99,235,0.28); }
    100% { box-shadow: 0 0 0 0 rgba(37,99,235,0.0), 0 14px 32px rgba(37,99,235,0.28); }
}
@keyframes operandPulseB {
    0% { box-shadow: 0 0 0 0 rgba(124,58,237,0.0), 0 14px 32px rgba(124,58,237,0.0); }
    35% { box-shadow: 0 0 0 8px rgba(124,58,237,0.18), 0 14px 32px rgba(124,58,237,0.28); }
    100% { box-shadow: 0 0 0 0 rgba(124,58,237,0.0), 0 14px 32px rgba(124,58,237,0.28); }
}
@keyframes operandPulseU {
    0% { box-shadow: 0 0 0 0 rgba(14,165,233,0.0), 0 14px 32px rgba(14,165,233,0.0); }
    35% { box-shadow: 0 0 0 8px rgba(14,165,233,0.18), 0 14px 32px rgba(14,165,233,0.28); }
    100% { box-shadow: 0 0 0 0 rgba(14,165,233,0.0), 0 14px 32px rgba(14,165,233,0.28); }
}

.btn-icon {
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

.btn-text {
    font-size: 0.75rem;
    letter-spacing: 0.06em;
}

.btn-arrow {
    font-size: 1rem;
    font-weight: 700;
    color: var(--color-primary-strong);
    line-height: 1;
}

/* Ensure arrow icons become visible on selected (blue) buttons */
.binary-btn.selected .btn-arrow,
.unary-btn.selected .btn-arrow {
    color: white;
}

.primitive-btn.enabled,
.transform-btn.enabled,
.binary-btn.enabled {
    opacity: 1;
}

/* ------------------------------------------------------------------
   Responsive adjustments - DISABLED to maintain fixed 4-column layout
------------------------------------------------------------------- */

/* 禁用响应式布局变化，保持固定4列布局 */
/* @media (max-width: 1400px) {
    body {
        overflow-y: auto;
    }

    .progress-bar {
        flex-wrap: wrap;
        justify-content: center;
        gap: 0.75rem 1.25rem;
        text-align: center;
    }

    .progress-track {
        max-width: none;
        width: min(540px, 100%);
    }

    .content-area {
        grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
        grid-template-rows: repeat(3, auto);
        grid-template-areas:
            "points preview"
            "target workspace"
            "controls program";
        padding: 1rem 1.25rem;
        gap: 1.1rem;
        align-content: start;
    }

    .panel-card {
        min-height: 0;
    }

    .operations-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .primitives-grid-inline {
        grid-template-columns: repeat(3, minmax(68px, 1fr));
        padding: 0.45rem;
    }
} */

/* @media (max-width: 1024px) {
    .content-area {
        grid-template-columns: minmax(0, 1fr);
        grid-template-rows: repeat(6, auto);
        grid-template-areas:
            "points"
            "preview"
            "target"
            "workspace"
            "controls"
            "program";
        gap: 0.95rem;
    }

    .panel-card {
        padding: 1rem 1.1rem;
    }

    .program-card {
        max-height: none;
        overflow: visible;
    }

    .operations-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
    }

    .primitives-grid-inline {
        grid-template-columns: repeat(3, minmax(68px, 1fr));
        padding: 0.4rem;
    }

    .binary-preview-body,
    .binary-preview-footer {
        justify-content: center;
    }
} */

/* @media (max-width: 900px) {
    .content-area {
        padding: 0.9rem 1rem 1.1rem;
    }

    .panel-card {
        border-radius: 0;
        box-shadow: 0 12px 28px rgba(15, 23, 42, 0.12);
    }

    .pattern-view,
    .workspace-canvas {
        min-height: 260px;
    }

    .program-card {
        gap: 0.85rem;
        max-height: none;
        overflow: visible;
    }
} */

/* @media (max-width: 768px) {
    .progress-bar {
        flex-direction: column;
        align-items: stretch;
        text-align: center;
        padding: 0.9rem 1.1rem;
        gap: 0.65rem;
    }

    .progress-track {
        width: 100%;
    }

    .progress-info {
        font-size: 0.9rem;
    }

    .panel-card {
        padding: 0.95rem 1rem;
    }

    .pattern-view,
    .workspace-canvas {
        padding: 0.65rem;
        min-height: 220px;
    }

    .operations-grid {
        grid-template-columns: repeat(2, minmax(0, 1fr));
        gap: 0.65rem;
    }

    .primitives-grid-inline {
        grid-template-columns: repeat(3, minmax(68px, 1fr));
        gap: 0.65rem;
    }

    .primitive-btn {
        min-height: 0;
    }
} */

/* @media (max-width: 640px) {
    .welcome-screen {
        align-items: flex-start;
        padding: 1.5rem 0;
    }

    .welcome-content {
        margin: 0 auto;
        padding: clamp(1.8rem, 4vw, 2.4rem);
        border-radius: 0;
    }

    .panel-card {
        padding: 0.9rem;
    }

    .operations-grid,
    .primitives-grid-inline {
        grid-template-columns: minmax(0, 1fr);
    }

    .btn,
    .transform-btn,
    .binary-btn,
    .primitive-btn {
        width: 100%;
    }

    .program-header {
        flex-direction: column;
        align-items: stretch;
    }

    .program-header .btn {
        width: 100%;
    }

    .binary-preview-body {
        justify-content: center;
        text-align: center;
    }

    .binary-preview-body,
    .binary-preview-footer {
        gap: 0.6rem;
    }
} */

/* Responsive scaling: 缩放由JavaScript动态控制，保持固定布局 */
/* 移除所有自动缩放的媒体查询，改用JavaScript计算 */
/* @media (max-width: 1400px) {
    :root { --ui-scale: 0.85; }
}

@media (max-width: 1280px) {
    :root { --ui-scale: 0.75; }
}

@media (max-width: 1024px) {
    :root { --ui-scale: 0.65; }
}

@media (max-width: 768px) {
    :root { --ui-scale: 0.55; }
}

@media (max-width: 640px) {
    :root { --ui-scale: 0.48; }
}

@media (max-width: 480px) {
    body {
        font-size: 15px;
    }

    .progress-bar {
        padding: 0.85rem 0.95rem;
    }

    .panel-card {
        padding: 0.85rem;
        border-radius: 0;
    }

    .panel-title {
        margin-bottom: 0.75rem;
    }

    .panel-subtitle {
        margin-bottom: 0.5rem;
    }

    .pattern-view,
    .workspace-canvas {
        min-height: 200px;
    }

    .operations-log {
        max-height: 260px;
    }

    .binary-preview-body {
        padding: 0.7rem 0.8rem;
    }

    .binary-preview-footer {
        flex-direction: column;
        align-items: stretch;
    }

    .binary-preview-footer .btn {
        width: 100%;
    }
} */

/* Modal System (Ethics, Instruction, Comprehension) ----------------------------------- */

.modal-overlay {
    position: fixed;
    inset: 0;
    display: none;
    align-items: center;
    justify-content: center;
    background: rgba(15, 23, 42, 0.85);
    backdrop-filter: blur(4px);
    z-index: 2000;
    animation: fadeIn 0.3s ease-out;
}

.modal-overlay.active {
    display: flex !important;
}

.modal-container {
    background: var(--color-surface);
    border-radius: 8px;
    max-width: 800px;
    width: 92%;
    max-height: 90vh;
    display: flex;
    flex-direction: column;
    box-shadow: 0 25px 80px rgba(0, 0, 0, 0.4);
    border: 1px solid var(--color-border);
    overflow: hidden;
}

/* Ethics/Consent specific styling */
.ethics-container {
    max-width: 900px;
}

.modal-scroll-content {
    padding: 2.5rem 3rem;
    overflow-y: auto;
    max-height: calc(90vh - 120px);
    line-height: 1.7;
    color: var(--color-text);
}

.modal-scroll-content h2 {
    font-size: 1.85rem;
    font-weight: 700;
    color: var(--color-text);
    margin: 0 0 1.5rem;
}

.modal-scroll-content p {
    margin: 0 0 1.25rem;
}

.modal-scroll-content ul, 
.modal-scroll-content ol {
    margin: 1rem 0 1.5rem 2rem;
    padding: 0;
}

.modal-scroll-content li {
    margin: 0.6rem 0;
    line-height: 1.6;
}

.modal-scroll-content strong {
    color: var(--color-text);
    font-weight: 700;
}

.modal-scroll-content a {
    color: var(--color-primary);
    text-decoration: none;
    font-weight: 500;
}

.modal-scroll-content a:hover {
    text-decoration: underline;
}

.modal-scroll-content hr {
    margin: 2rem 0;
    border: none;
    border-top: 2px solid var(--color-border);
}

/* Custom scrollbar for modal content */
.modal-scroll-content::-webkit-scrollbar {
    width: 8px;
}

.modal-scroll-content::-webkit-scrollbar-track {
    background: var(--color-surface-soft);
    border-radius: 4px;
}

.modal-scroll-content::-webkit-scrollbar-thumb {
    background: var(--color-border-strong);
    border-radius: 4px;
}

.modal-scroll-content::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-muted);
}

/* Instruction & Comprehension modals */
.modal-header {
    padding: 2rem 2.5rem 1.5rem;
    border-bottom: 2px solid var(--color-border);
    background: var(--color-surface-soft);
}

.modal-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--color-text);
    margin: 0;
}

.modal-body {
    padding: 2rem 2.5rem;
    flex: 1;
    overflow-y: auto;
    line-height: 1.7;
    color: var(--color-text);
}

.modal-body h2 {
    font-size: 1.6rem;
    font-weight: 700;
    margin: 0 0 1rem;
}

.modal-body h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-text);
    margin: 1.75rem 0 0.75rem;
}

.modal-body p {
    margin: 0 0 1rem;
}

.modal-body ul {
    margin: 0.75rem 0 1.25rem 1.5rem;
    padding: 0;
}

.modal-body li {
    margin: 0.5rem 0;
}

.modal-body strong {
    color: var(--color-primary-strong);
    font-weight: 700;
}

.instruction-tip {
    padding: 1rem 1.25rem;
    background: #fef3c7;
    border-left: 4px solid #f59e0b;
    margin: 1.5rem 0;
    border-radius: 4px;
    font-size: 0.95rem;
}

.instruction-tip strong {
    color: #92400e;
}

.modal-footer {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.25rem 2.5rem;
    border-top: 2px solid var(--color-border);
    background: var(--color-surface-soft);
    gap: 1rem;
}

.modal-footer button {
    flex: 0 0 auto;
}

/* Button Styles - 优化为1037px布局 */
.btn {
    padding: 0.5rem 1rem;
    font-size: 0.8rem;
    font-weight: 600;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: var(--font-sans);
}

.btn-secondary {
    background: var(--color-surface);
    color: var(--color-text-muted);
    border: 1px solid var(--color-border);
}

.btn-secondary:hover {
    background: var(--color-surface-soft);
    color: var(--color-text);
    border-color: var(--color-border-strong);
}

.btn-primary {
    background: var(--color-primary);
    color: white;
    border: 1px solid var(--color-primary);
}

.btn-primary:hover {
    background: var(--color-primary-strong);
}

.btn-primary:disabled {
    background: var(--color-text-muted);
    border-color: var(--color-text-muted);
    cursor: not-allowed;
    opacity: 0.6;
}

/* Red danger button for End Free Play - REMOVED (auto-timer replaced manual button) */
/*
#endFreePlayBtn {
    background: #dc2626 !important;
    color: white !important;
    border: none !important;
    transition: all 0.2s ease;
}

#endFreePlayBtn:hover {
    background: #b91c1c !important;
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(220, 38, 38, 0.3);
}

#endFreePlayBtn:active {
    transform: translateY(0);
    box-shadow: 0 2px 4px rgba(220, 38, 38, 0.3);
}
*/

.btn-large {
    padding: 1rem 2.5rem;
    font-size: 1.05rem;
    font-weight: 700;
}

/* Comprehension Check Styles */
.question-block {
    margin: 1.5rem 0;
    padding: 1.25rem 1.5rem;
    background: var(--color-surface-soft);
    border-radius: 6px;
    border: 1px solid var(--color-border);
}

.question-text {
    margin: 0 0 1rem;
    font-size: 1rem;
    color: var(--color-text);
    line-height: 1.5;
}

.radio-option {
    display: flex;
    align-items: flex-start;
    padding: 0.7rem 0.9rem;
    margin: 0.5rem 0;
    cursor: pointer;
    border-radius: 5px;
    transition: all 0.15s ease;
    border: 2px solid transparent;
    background: white;
}

.radio-option:hover {
    background: rgba(37, 99, 235, 0.06);
    border-color: rgba(37, 99, 235, 0.2);
}

.radio-option input[type="radio"] {
    margin: 0.3rem 0.9rem 0 0;
    cursor: pointer;
    flex-shrink: 0;
    width: 18px;
    height: 18px;
}

.radio-option span {
    flex: 1;
    line-height: 1.6;
}

.radio-option input[type="radio"]:checked + span {
    font-weight: 600;
    color: var(--color-primary-strong);
}

.form-feedback {
    display: none;
    margin: 1.5rem 0 0;
    padding: 1rem 1.25rem;
    border-radius: 6px;
    font-size: 0.95rem;
}

.form-feedback .success,
.form-feedback p.success {
    background: #d1fae5;
    color: #065f46;
    border: 2px solid #10b981;
    padding: 1rem 1.25rem;
    border-radius: 6px;
    font-weight: 600;
}

.form-feedback .error,
.form-feedback p.error {
    background: #fee2e2;
    color: #991b1b;
    border: 2px solid #ef4444;
    padding: 1rem 1.25rem;
    border-radius: 6px;
    font-weight: 600;
}

.comprehension-submit-btn {
    display: block;
    width: 100%;
    padding: 0.9rem 1.5rem;
    background: var(--color-primary);
    color: white;
    border: none;
    border-radius: 6px;
    font-size: 1.05rem;
    font-weight: 700;
    cursor: pointer;
    transition: background 0.2s ease;
    margin-top: 2rem;
}

.comprehension-submit-btn:hover {
    background: var(--color-primary-strong);
}

.success-message,
.error-message {
    text-align: center;
    padding: 2rem;
    margin: 2rem 0;
    border-radius: 8px;
}

.success-message {
    background: #ecfdf5;
    border: 2px solid #10b981;
}

.success-message h3 {
    color: #065f46;
    font-size: 1.5rem;
    margin: 0 0 0.75rem;
}

.success-message p {
    color: #047857;
    font-size: 1.05rem;
    margin: 0;
}

.error-message {
    background: #fef2f2;
    border: 2px solid #ef4444;
}

.error-message h3 {
    color: #991b1b;
    font-size: 1.4rem;
    margin: 0 0 0.75rem;
}

.error-message p {
    color: #b91c1c;
    font-size: 1.05rem;
    margin: 0;
}

.comprehension-pass-btn,
.comprehension-retry-btn {
    display: block;
    width: 100%;
    padding: 1rem 2rem;
    font-size: 1.1rem;
    font-weight: 700;
    border: none;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s ease;
    margin-top: 1.5rem;
}

.comprehension-pass-btn {
    background: #059669;
    color: white;
}

.comprehension-pass-btn:hover {
    background: #047857;
}

.comprehension-retry-btn {
    background: var(--color-surface);
    color: var(--color-text);
    border: 2px solid var(--color-border-strong);
}

.comprehension-retry-btn:hover {
    background: var(--color-surface-soft);
}

/* Responsive adjustments */
@media (max-width: 768px) {
    .modal-container {
        width: 96%;
        max-height: 95vh;
    }
    
    .modal-scroll-content,
    .modal-header,
    .modal-body,
    .modal-footer {
        padding-left: 1.5rem;
        padding-right: 1.5rem;
    }
    
    .btn {
        padding: 0.6rem 1.2rem;
        font-size: 0.9rem;
    }
    
    .btn-large {
        padding: 0.85rem 2rem;
        font-size: 1rem;
    }
}

/* Completion Modal Styles */
.completion-modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.7);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10000;
    animation: fadeIn 0.3s ease;
}

.completion-content {
    background: var(--color-surface);
    border-radius: 16px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    max-width: 600px;
    width: 90%;
    padding: 0;
    animation: slideUp 0.4s ease;
}

.completion-header {
    background: linear-gradient(135deg, #2563eb 0%, #1d4ed8 100%);
    color: white;
    padding: 2rem;
    border-radius: 16px 16px 0 0;
    text-align: center;
}

.completion-header h2 {
    font-size: 2rem;
    font-weight: 700;
    margin: 0;
}

.completion-body {
    padding: 2rem;
}

.completion-message {
    font-size: 1.1rem;
    color: var(--color-text);
    text-align: center;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.completion-stats {
    background: var(--color-surface-soft);
    border: 2px solid var(--color-border);
    border-radius: 12px;
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

.stat-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 1.2rem;
}

.stat-label {
    font-weight: 600;
    color: var(--color-text-muted);
}

.stat-value {
    font-weight: 700;
    color: var(--color-primary);
    font-size: 1.4rem;
}

.completion-actions {
    display: flex;
    justify-content: center;
    margin-bottom: 1rem;
}

.completion-actions .btn {
    min-width: 250px;
}

.completion-note {
    text-align: center;
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin: 0;
    line-height: 1.5;
}

.completion-contact {
    text-align: center;
    font-size: 0.95rem;
    color: #1f2937;
    margin: 1.5rem 0 0.5rem 0;
    padding: 1rem;
    background: #e0f2fe;
    border-radius: 6px;
    border-left: 4px solid #0284c7;
}

.completion-contact strong {
    color: #0369a1;
    font-weight: 600;
}

.completion-feedback {
    text-align: center;
    font-size: 0.85rem;
    color: #6b7280;
    margin: 0.5rem 0 0 0;
    font-style: italic;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }
    to {
        opacity: 1;
    }
}

@keyframes slideUp {
    from {
        transform: translateY(30px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}