/* ============================================
   Classroom Sync — Teacher-Led Regulation
   Clean, professional, dashboard aesthetic
   ============================================ */

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

:root {
    --bg-dark: #0a0c10;
    --bg-card: #12151c;
    --bg-hover: #1a1e28;
    --border: rgba(255,255,255,0.08);
    
    --calm: #68d391;
    --calm-dim: rgba(104, 211, 145, 0.15);
    --alert: #fbd38d;
    --alert-dim: rgba(251, 211, 141, 0.15);
    --stressed: #fc8181;
    --stressed-dim: rgba(252, 129, 129, 0.15);
    --coherence: #63b3ed;
    --coherence-dim: rgba(99, 179, 237, 0.15);
    
    --accent: #90cdf4;
    --accent-dim: rgba(144, 205, 244, 0.1);
    
    --text-primary: #e2e8f0;
    --text-secondary: rgba(226, 232, 240, 0.7);
    --text-muted: rgba(226, 232, 240, 0.4);
    
    --font-display: 'Space Grotesk', sans-serif;
    --font-body: 'DM Sans', sans-serif;
    
    --radius: 12px;
    --radius-sm: 8px;
    --transition: 0.3s ease;
}

body {
    font-family: var(--font-body);
    background: var(--bg-dark);
    color: var(--text-primary);
    min-height: 100vh;
    overflow-x: hidden;
}

.app-container {
    width: 100%;
    min-height: 100vh;
}

/* Screens */
.screen {
    position: fixed;
    inset: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transition: opacity 0.5s ease;
}

.screen.active {
    opacity: 1;
    visibility: visible;
}

.screen-content {
    max-width: 500px;
    width: 100%;
    padding: 40px 20px;
    text-align: center;
}

/* Role Selection */
.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 40px;
}

.logo-icon {
    font-size: 1.5rem;
    color: var(--accent);
    font-weight: 300;
}

.logo-text {
    font-family: var(--font-display);
    font-size: 1rem;
    letter-spacing: 0.15em;
    color: var(--text-secondary);
}

.logo-small {
    font-size: 1.2rem;
    color: var(--accent);
}

.welcome-title {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 10px;
}

.welcome-subtitle {
    color: var(--text-secondary);
    margin-bottom: 40px;
}

.role-options {
    display: flex;
    flex-direction: column;
    gap: 16px;
    margin-bottom: 30px;
}

.role-btn {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    padding: 24px;
    cursor: pointer;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
    transition: all var(--transition);
}

.role-btn:hover {
    background: var(--bg-hover);
    border-color: var(--accent);
    transform: translateY(-2px);
}

.role-icon {
    font-size: 2.5rem;
}

.role-title {
    font-family: var(--font-display);
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-primary);
}

.role-desc {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.teacher-btn:hover {
    border-color: var(--coherence);
    box-shadow: 0 0 30px var(--coherence-dim);
}

.student-btn:hover {
    border-color: var(--calm);
    box-shadow: 0 0 30px var(--calm-dim);
}

.demo-note {
    font-size: 0.85rem;
    color: var(--text-muted);
    font-style: italic;
}

/* ============================================
   Teacher Dashboard
   ============================================ */

.teacher-layout {
    width: 100%;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

.teacher-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 24px;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 20px;
}

.session-info {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.session-label {
    font-size: 0.7rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.session-code {
    font-family: var(--font-display);
    font-size: 0.95rem;
    color: var(--accent);
    font-weight: 600;
}

.header-center {
    position: absolute;
    left: 50%;
    transform: translateX(-50%);
}

.class-status {
    font-family: var(--font-display);
    font-size: 1rem;
    color: var(--text-secondary);
}

.header-right {
    display: flex;
    align-items: center;
    gap: 20px;
}

.student-count {
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.student-count span {
    color: var(--calm);
    font-weight: 600;
}

.end-session-btn {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-muted);
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: all var(--transition);
}

.end-session-btn:hover {
    border-color: var(--stressed);
    color: var(--stressed);
}

/* Main Dashboard */
.teacher-main {
    flex: 1;
    display: grid;
    grid-template-columns: 1fr 350px;
    gap: 24px;
    padding: 24px;
    overflow: auto;
}

.section-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 20px;
}

.section-header h2 {
    font-family: var(--font-display);
    font-size: 1.1rem;
    font-weight: 600;
}

/* Heatmap */
.heatmap-section {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 24px;
    border: 1px solid var(--border);
}

.heatmap-legend {
    display: flex;
    gap: 16px;
}

.legend-item {
    font-size: 0.8rem;
    display: flex;
    align-items: center;
    gap: 6px;
}

.legend-item::before {
    content: '';
    width: 10px;
    height: 10px;
    border-radius: 50%;
}

.legend-item.calm::before { background: var(--calm); }
.legend-item.alert::before { background: var(--alert); }
.legend-item.stressed::before { background: var(--stressed); }

/* Waiting for Students */
.waiting-for-students {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 60px 20px;
    text-align: center;
    min-height: 250px;
}

.waiting-for-students.hidden {
    display: none;
}

.waiting-icon-large {
    font-size: 4rem;
    margin-bottom: 16px;
    animation: gentle-bounce 2s ease-in-out infinite;
}

@keyframes gentle-bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-8px); }
}

.waiting-for-students h3 {
    font-family: var(--font-display);
    font-size: 1.3rem;
    color: var(--text-primary);
    margin-bottom: 8px;
}

.waiting-for-students p {
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.share-code-box {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--bg-dark);
    padding: 12px 16px;
    border-radius: var(--radius);
    border: 2px dashed var(--border);
}

.share-code {
    font-family: var(--font-display);
    font-size: 1.5rem;
    color: var(--accent);
    font-weight: 700;
    letter-spacing: 0.1em;
}

.copy-code-btn {
    background: var(--accent-dim);
    border: 1px solid var(--accent);
    color: var(--accent);
    padding: 8px 16px;
    border-radius: 6px;
    font-size: 0.85rem;
    cursor: pointer;
    transition: var(--transition);
}

.copy-code-btn:hover {
    background: var(--accent);
    color: var(--bg-dark);
}

.copy-code-btn.copied {
    background: var(--calm);
    border-color: var(--calm);
    color: var(--bg-dark);
}

.class-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(60px, 1fr));
    gap: 12px;
    margin-bottom: 24px;
    min-height: 120px;
}

.class-grid.hidden {
    display: none;
}

/* Empty state message */
.class-grid:empty::after {
    content: 'No students yet';
    color: var(--text-muted);
    font-size: 0.9rem;
    grid-column: 1 / -1;
    text-align: center;
    padding: 40px;
}

.student-dot {
    aspect-ratio: 1;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 0.75rem;
    font-weight: 600;
    color: rgba(0,0,0,0.6);
    transition: all 0.5s ease;
    cursor: pointer;
    position: relative;
}

.student-dot.calm { background: var(--calm); }
.student-dot.alert { background: var(--alert); }
.student-dot.stressed { background: var(--stressed); }

.student-dot:hover {
    transform: scale(1.1);
    z-index: 10;
}

.student-dot::after {
    content: attr(data-name);
    position: absolute;
    bottom: calc(100% + 8px);
    left: 50%;
    transform: translateX(-50%);
    background: var(--bg-dark);
    color: var(--text-primary);
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 0.75rem;
    white-space: nowrap;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.2s ease;
}

.student-dot:hover::after {
    opacity: 1;
}

.class-stats {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}

.stat {
    text-align: center;
    padding: 16px;
    background: var(--bg-dark);
    border-radius: var(--radius-sm);
}

.stat-value {
    font-family: var(--font-display);
    font-size: 1.8rem;
    font-weight: 700;
    display: block;
    margin-bottom: 4px;
}

.stat-value.calm { color: var(--calm); }
.stat-value.alert { color: var(--alert); }
.stat-value.stressed { color: var(--stressed); }
.stat-value.coherence { color: var(--coherence); }

.stat-label {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* Controls */
.controls-section {
    background: var(--bg-card);
    border-radius: var(--radius);
    padding: 24px;
    border: 1px solid var(--border);
}

.exercise-options {
    display: flex;
    flex-direction: column;
    gap: 10px;
}

.exercise-btn {
    display: flex;
    align-items: center;
    gap: 12px;
    background: var(--bg-dark);
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    padding: 14px 16px;
    cursor: pointer;
    transition: all var(--transition);
    text-align: left;
}

.exercise-btn:hover {
    background: var(--bg-hover);
    border-color: var(--accent);
}

.ex-icon {
    font-size: 1.3rem;
}

.ex-name {
    flex: 1;
    font-family: var(--font-display);
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--text-primary);
}

.ex-time {
    font-size: 0.8rem;
    color: var(--text-muted);
}

/* Exercise Overlay */
.exercise-overlay {
    position: fixed;
    inset: 0;
    background: rgba(10, 12, 16, 0.95);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1000;
    transition: opacity 0.5s ease;
}

.exercise-overlay.hidden {
    opacity: 0;
    pointer-events: none;
}

.exercise-display {
    text-align: center;
    max-width: 500px;
    padding: 40px;
}

.exercise-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    margin-bottom: 40px;
}

.exercise-name {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--accent);
}

.stop-btn {
    background: transparent;
    border: 1px solid var(--stressed);
    color: var(--stressed);
    padding: 8px 20px;
    border-radius: 20px;
    cursor: pointer;
    transition: all var(--transition);
}

.stop-btn:hover {
    background: var(--stressed-dim);
}

.breath-visual {
    margin: 40px 0;
}

.breath-circle {
    width: 180px;
    height: 180px;
    margin: 0 auto 30px;
    border: 4px solid var(--accent);
    border-radius: 50%;
    transition: all 4s ease;
    box-shadow: 0 0 40px var(--accent-dim);
}

.breath-circle.expand {
    transform: scale(1.3);
    box-shadow: 0 0 60px var(--coherence-dim);
}

.breath-circle.contract {
    transform: scale(0.7);
    opacity: 0.7;
}

.breath-instruction {
    font-family: var(--font-display);
    font-size: 1.5rem;
    color: var(--text-primary);
}

.exercise-progress {
    display: flex;
    align-items: center;
    gap: 15px;
    margin-bottom: 30px;
}

.exercise-progress .progress-bar {
    flex: 1;
    height: 6px;
    background: var(--bg-card);
    border-radius: 3px;
    overflow: hidden;
}

.exercise-progress .progress-fill {
    height: 100%;
    background: var(--accent);
    transition: width 1s linear;
}

.time-remaining {
    font-family: var(--font-display);
    font-size: 1.2rem;
    color: var(--text-secondary);
    min-width: 50px;
}

.live-coherence {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.coherence-label {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.coherence-value {
    font-family: var(--font-display);
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--coherence);
}

/* ============================================
   Student View
   ============================================ */

.student-layout {
    width: 100%;
    height: 100vh;
    display: flex;
    flex-direction: column;
}

.student-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 16px 24px;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
}

.student-name-display {
    font-family: var(--font-display);
    font-size: 0.95rem;
    color: var(--text-primary);
    font-weight: 500;
}

.session-joined {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.session-joined span {
    color: var(--accent);
}

.student-state {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: opacity 0.5s ease;
}

.student-state.hidden {
    display: none;
}

/* Waiting State */
.waiting-content {
    text-align: center;
}

.waiting-icon {
    font-size: 4rem;
    margin-bottom: 20px;
    animation: wave 2s ease-in-out infinite;
}

@keyframes wave {
    0%, 100% { transform: rotate(-10deg); }
    50% { transform: rotate(10deg); }
}

.waiting-content h2 {
    font-family: var(--font-display);
    font-size: 1.8rem;
    margin-bottom: 10px;
}

.waiting-content p {
    color: var(--text-secondary);
    margin-bottom: 30px;
}

.pulse-ring {
    width: 60px;
    height: 60px;
    margin: 0 auto;
    border: 2px solid var(--accent);
    border-radius: 50%;
    animation: pulse-ring 2s ease-in-out infinite;
}

@keyframes pulse-ring {
    0% { transform: scale(0.8); opacity: 1; }
    100% { transform: scale(1.5); opacity: 0; }
}

/* Student Exercise */
.student-exercise-content {
    text-align: center;
    padding: 40px;
}

.exercise-label {
    font-family: var(--font-display);
    font-size: 1.2rem;
    color: var(--accent);
    margin-bottom: 40px;
    letter-spacing: 0.1em;
}

.student-breath-visual {
    margin: 40px 0;
}

.student-breath-circle {
    width: 200px;
    height: 200px;
    margin: 0 auto;
    border: 5px solid var(--calm);
    border-radius: 50%;
    transition: all 4s ease;
    box-shadow: 0 0 50px var(--calm-dim);
}

.student-breath-circle.expand {
    transform: scale(1.4);
    box-shadow: 0 0 80px var(--calm-dim);
}

.student-breath-circle.contract {
    transform: scale(0.6);
    opacity: 0.6;
}

.student-instruction {
    font-family: var(--font-display);
    font-size: 2rem;
    color: var(--text-primary);
    margin-bottom: 40px;
}

.student-feedback {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.feedback-dot {
    width: 12px;
    height: 12px;
    background: var(--calm);
    border-radius: 50%;
    animation: feedback-pulse 1.5s ease-in-out infinite;
}

@keyframes feedback-pulse {
    0%, 100% { opacity: 0.5; }
    50% { opacity: 1; }
}

.feedback-text {
    font-size: 0.9rem;
    color: var(--text-muted);
}

/* Complete State */
.complete-content {
    text-align: center;
}

.complete-icon {
    font-size: 4rem;
    width: 100px;
    height: 100px;
    background: var(--calm);
    color: var(--bg-dark);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    animation: pop-in 0.5s ease;
}

@keyframes pop-in {
    0% { transform: scale(0); }
    70% { transform: scale(1.1); }
    100% { transform: scale(1); }
}

.complete-content h2 {
    font-family: var(--font-display);
    font-size: 2rem;
    color: var(--calm);
    margin-bottom: 10px;
}

.complete-message {
    color: var(--text-secondary);
}

/* Responsive */
@media (max-width: 900px) {
    .teacher-main {
        grid-template-columns: 1fr;
    }
    
    .class-grid {
        grid-template-columns: repeat(4, 1fr);
    }
    
    .header-center {
        display: none;
    }
}

@media (max-width: 500px) {
    .class-grid {
        grid-template-columns: repeat(4, 1fr);
        gap: 8px;
    }
    
    .class-stats {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .header-right .student-count {
        display: none;
    }
}

/* ==================== JOIN SCREEN ==================== */

.join-title {
    font-family: var(--font-display);
    font-size: 2rem;
    margin-bottom: 10px;
    background: linear-gradient(135deg, var(--calm), var(--accent));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.join-subtitle {
    color: var(--text-secondary);
    margin-bottom: 40px;
}

/* Join Form */
.join-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
    margin-bottom: 30px;
}

.input-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
    align-items: center;
}

.input-label {
    font-size: 0.8rem;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.name-input {
    background: var(--bg-card);
    border: 2px solid var(--border);
    border-radius: var(--radius);
    padding: 14px 20px;
    font-size: 1rem;
    font-family: var(--font-body);
    text-align: center;
    color: var(--text-primary);
    width: 100%;
    max-width: 300px;
    transition: var(--transition);
}

.name-input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 4px var(--accent-dim);
}

.name-input::placeholder {
    color: var(--text-muted);
}

.name-input:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.anonymous-option {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-top: 4px;
}

.anonymous-option input[type="checkbox"] {
    width: 18px;
    height: 18px;
    accent-color: var(--accent);
    cursor: pointer;
}

.checkbox-label {
    user-select: none;
}

.code-input-container {
    margin-bottom: 30px;
}

.code-input {
    background: var(--bg-card);
    border: 2px solid var(--border);
    border-radius: var(--radius);
    padding: 20px 30px;
    font-size: 2rem;
    font-family: var(--font-display);
    letter-spacing: 0.2em;
    text-align: center;
    color: var(--text-primary);
    width: 100%;
    max-width: 300px;
    text-transform: uppercase;
    transition: var(--transition);
}

.code-input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 4px var(--accent-dim);
}

.code-input::placeholder {
    color: var(--text-muted);
    letter-spacing: 0.1em;
}

.code-error {
    color: var(--stressed);
    margin-top: 15px;
    font-size: 0.9rem;
}

.code-error.hidden {
    display: none;
}

.join-btn {
    background: linear-gradient(135deg, var(--calm), #38a169);
    border: none;
    color: white;
    padding: 16px 40px;
    font-size: 1.1rem;
    font-family: var(--font-display);
    font-weight: 600;
    border-radius: var(--radius);
    cursor: pointer;
    transition: var(--transition);
    margin-bottom: 20px;
}

.join-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(104, 211, 145, 0.3);
}

.back-btn {
    background: transparent;
    border: none;
    color: var(--text-secondary);
    font-size: 0.95rem;
    cursor: pointer;
    padding: 10px 20px;
    transition: var(--transition);
}

.back-btn:hover {
    color: var(--text-primary);
}

/* Connection Status Bar */
.connection-status-bar {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 8px 16px;
    border-radius: 20px;
    background: rgba(245, 158, 11, 0.1);
    border: 1px solid rgba(245, 158, 11, 0.3);
    margin-bottom: 20px;
    font-size: 0.85rem;
    transition: all 0.3s ease;
}

.status-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #f59e0b;
    animation: pulse-dot 2s infinite;
}

@keyframes pulse-dot {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.status-text {
    color: var(--text-secondary);
}

/* Toast Animation */
@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateX(-50%) translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateX(-50%) translateY(0);
    }
}