:root {
    --bg-primary: #0a0e1a;
    --bg-secondary: #151b2d;
    --bg-tertiary: #1e2638;
    --bg-card: #1a2035;

    --text-primary: #e8eaed;
    --text-secondary: #9aa0b3;
    --text-muted: #6b7280;

    --accent-blue: #3b82f6;
    --accent-purple: #8b5cf6;
    --accent-green: #10b981;
    --accent-yellow: #f59e0b;
    --accent-red: #ef4444;

    --border-color: #2d3548;
    --hover-bg: #252d42;

    --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.3);
    --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.4);
    --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.5);
    --shadow-xl: 0 20px 25px -5px rgb(0 0 0 / 0.6);

    --radius-sm: 6px;
    --radius-md: 10px;
    --radius-lg: 14px;
    --radius-xl: 18px;
}

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

.hidden {
    display: none !important;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    overflow-x: hidden;
}

/* ===== LOGIN PAGE ===== */
#loginPage {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background: linear-gradient(135deg, #0a0e1a 0%, #1e2638 100%);
    position: relative;
    overflow: hidden;
}

#loginPage::before {
    content: '';
    position: absolute;
    width: 600px;
    height: 600px;
    background: radial-gradient(circle, rgba(59, 130, 246, 0.1) 0%, transparent 70%);
    top: -300px;
    right: -300px;
    animation: pulse 8s ease-in-out infinite;
}

#loginPage::after {
    content: '';
    position: absolute;
    width: 400px;
    height: 400px;
    background: radial-gradient(circle, rgba(139, 92, 246, 0.1) 0%, transparent 70%);
    bottom: -200px;
    left: -200px;
    animation: pulse 10s ease-in-out infinite;
}

@keyframes pulse {

    0%,
    100% {
        transform: scale(1);
        opacity: 0.5;
    }

    50% {
        transform: scale(1.1);
        opacity: 0.8;
    }
}

.login-box {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 400px;
    padding: 40px;
    background: var(--bg-card);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    border: 1px solid var(--border-color);
}

.logo {
    text-align: center;
    margin-bottom: 30px;
}

.logo-img {
    width: 80px;
    height: 80px;
    object-fit: contain;
    margin-bottom: 15px;
    filter: drop-shadow(0 4px 6px rgba(0, 0, 0, 0.3));
}

.logo h1 {
    font-size: 1.8rem;
    font-weight: 700;
    background: linear-gradient(to right, var(--accent-blue), var(--accent-purple));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 5px;
}

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

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: var(--text-secondary);
    font-size: 0.9rem;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 12px;
    background: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    color: var(--text-primary);
    font-size: 1rem;
    transition: all 0.2s;
}

.form-group input:focus {
    outline: none;
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.remember-me {
    display: flex;
    align-items: center;
    margin-bottom: 25px;
}

.checkbox-label {
    display: flex;
    align-items: center;
    gap: 8px;
    cursor: pointer;
    user-select: none;
}

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

.checkbox-label span {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

.btn-primary {
    width: 100%;
    padding: 12px;
    background: linear-gradient(to right, var(--accent-blue), #2563eb);
    color: white;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: transform 0.1s, box-shadow 0.2s;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 10px;
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

.btn-primary:active {
    transform: translateY(0);
}

.btn-primary:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}

.error-message {
    margin-top: 15px;
    padding: 10px;
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.2);
    color: var(--accent-red);
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    text-align: center;
}

.spinner {
    width: 20px;
    height: 20px;
    border: 2px solid rgba(255, 255, 255, 0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

/* ===== DASHBOARD ===== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

.dashboard {
    padding-top: 20px;
}

.header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px solid var(--border-color);
}

.user-info h2 {
    font-size: 1.5rem;
    margin-bottom: 5px;
}

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

.btn-logout {
    padding: 8px 16px;
    background: var(--bg-card);
    border: 1px solid var(--border-color);
    color: var(--text-secondary);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all 0.2s;
}

.btn-logout:hover {
    background: var(--hover-bg);
    color: var(--text-primary);
}

/* ===== STATS CARDS ===== */
.stats-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.stat-card {
    background: var(--bg-card);
    padding: 20px;
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    display: flex;
    align-items: center;
    gap: 15px;
    transition: transform 0.2s;
}

.stat-card:hover {
    transform: translateY(-2px);
}

.stat-icon {
    width: 48px;
    height: 48px;
    background: var(--bg-secondary);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
}

.stat-info h3 {
    font-size: 1.5rem;
    font-weight: 700;
    line-height: 1;
    margin-bottom: 5px;
}

.stat-info p {
    color: var(--text-secondary);
    font-size: 0.85rem;
}

/* ===== ATTENDANCE GRID ===== */
.section-title {
    font-size: 1.2rem;
    margin-bottom: 20px;
    display: flex;
    align-items: center;
    gap: 10px;
}

.attendance-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 25px;
}

.attendance-card {
    background: var(--bg-card);
    border-radius: var(--radius-md);
    border: 1px solid var(--border-color);
    padding: 20px;
    transition: all 0.3s ease;
    animation: fadeIn 0.5s ease-out forwards;
    opacity: 0;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.attendance-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-color: var(--accent-blue);
}

.course-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 15px;
    gap: 15px;
}

.course-code {
    font-size: 0.8rem;
    color: var(--accent-blue);
    font-weight: 600;
    margin-bottom: 4px;
}

.course-name {
    font-size: 1rem;
    font-weight: 600;
    line-height: 1.3;
    max-width: 200px;
}

.attendance-badge {
    padding: 8px 16px;
    border-radius: 12px;
    font-weight: 800;
    font-size: 1.5rem;
    min-width: 80px;
    text-align: center;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.badge-high {
    background: rgba(16, 185, 129, 0.1);
    color: var(--accent-green);
    border: 1px solid rgba(16, 185, 129, 0.2);
}

.badge-medium {
    background: rgba(245, 158, 11, 0.1);
    color: var(--accent-yellow);
    border: 1px solid rgba(245, 158, 11, 0.2);
}

.badge-low {
    background: rgba(239, 68, 68, 0.1);
    color: var(--accent-red);
    border: 1px solid rgba(239, 68, 68, 0.2);
}

.course-stats {
    display: flex;
    justify-content: space-between;
    margin-bottom: 15px;
    padding: 10px;
    background: var(--bg-secondary);
    border-radius: var(--radius-sm);
}

.stat-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

.stat-item strong {
    color: var(--text-primary);
}

.progress-bar-container {
    height: 8px;
    background: var(--bg-secondary);
    border-radius: 4px;
    overflow: hidden;
    margin-bottom: 10px;
}

.progress-bar {
    height: 100%;
    background: var(--accent-red);
    border-radius: 4px;
    transition: width 1s ease-out;
}

.progress-bar.good {
    background: var(--accent-green);
}

/* ===== ATTENDANCE STATUS & PREDICTOR ===== */
.status-box {
    margin-top: 15px;
    padding: 12px;
    border-radius: var(--radius-sm);
    display: flex;
    align-items: flex-start;
    gap: 10px;
    font-size: 0.9rem;
    line-height: 1.4;
}

.status-warning {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.2);
    color: #fca5a5;
}

.status-success {
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.2);
    color: #6ee7b7;
}

.status-neutral {
    background: rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(59, 130, 246, 0.2);
    color: #93c5fd;
}

.status-icon {
    font-size: 1.2rem;
    flex-shrink: 0;
}

.predictor-box {
    margin-top: 15px;
    padding: 15px;
    background: rgba(59, 130, 246, 0.05);
    border: 1px solid rgba(59, 130, 246, 0.1);
    border-radius: var(--radius-md);
}

.predictor-title {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 12px;
}

.predictor-input-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 10px;
    margin-bottom: 10px;
}

.predictor-input-half {
    background: var(--bg-primary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 10px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    transition: all 0.2s;
    width: 100%;
}

.predictor-input-half:focus {
    outline: none;
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.2);
}

.btn-calculate {
    width: 100%;
    background: var(--accent-blue);
    color: white;
    border: none;
    padding: 12px;
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

.btn-calculate:hover {
    background: #2563eb;
    transform: translateY(-1px);
}

.btn-calculate:active {
    transform: translateY(0);
}

.calc-result {
    margin-top: 15px;
    min-height: 20px;
}

.result-summary {
    background: var(--bg-secondary);
    padding: 12px;
    border-radius: var(--radius-sm);
    margin-bottom: 12px;
}

.result-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 8px;
    font-weight: 600;
}

.result-details {
    display: flex;
    justify-content: space-between;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.stat-warning,
.stat-success,
.stat-neutral {
    display: flex;
    align-items: flex-start;
    gap: 10px;
    padding: 10px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    line-height: 1.4;
}

.stat-warning {
    background: rgba(239, 68, 68, 0.1);
    border: 1px solid rgba(239, 68, 68, 0.2);
    color: #fca5a5;
}

.stat-success {
    background: rgba(16, 185, 129, 0.1);
    border: 1px solid rgba(16, 185, 129, 0.2);
    color: #6ee7b7;
}

.stat-neutral {
    background: rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(59, 130, 246, 0.2);
    color: #93c5fd;
}

.stat-icon {
    font-size: 1.1rem;
    flex-shrink: 0;
}

.error-msg {
    color: var(--accent-red);
    font-size: 0.9rem;
    text-align: center;
    padding: 10px;
}

.loading {
    text-align: center;
    padding: 40px;
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }

    .dashboard {
        padding: 15px;
    }

    .header {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }

    .user-info h2 {
        font-size: 1.3rem;
    }

    .semester-info {
        font-size: 0.85rem;
    }

    .btn-logout {
        width: 100%;
        text-align: center;
        padding: 10px;
    }

    .stats-container {
        grid-template-columns: repeat(2, 1fr);
        gap: 10px;
    }

    .stat-card {
        padding: 14px;
    }

    .stat-icon {
        font-size: 2rem;
    }

    .stat-info h3 {
        font-size: 1.3rem;
    }

    .stat-info p {
        font-size: 0.8rem;
    }

    .attendance-grid {
        grid-template-columns: 1fr;
        gap: 15px;
    }

    .header-top {
        flex-direction: column;
        align-items: flex-start;
        gap: 10px;
    }

    .section-title {
        font-size: 1.3rem;
    }

    .sort-controls {
        width: 100%;
        justify-content: space-between;
    }

    .sort-select {
        flex: 1;
        min-width: 0;
    }

    .section-subtitle {
        font-size: 0.8rem;
    }

    .attendance-card {
        padding: 15px;
    }

    .course-code {
        font-size: 0.85rem;
    }

    .course-name {
        font-size: 0.95rem;
    }

    .attendance-badge {
        font-size: 1.1rem;
        padding: 6px 12px;
    }

    .course-stats {
        gap: 10px;
    }

    .stat-item {
        font-size: 0.85rem;
    }

    .status-box {
        padding: 10px;
        font-size: 0.85rem;
    }

    .predictor-box {
        padding: 12px;
    }

    .predictor-title {
        font-size: 0.85rem;
    }

    .predictor-input-row {
        gap: 8px;
    }

    .predictor-input-half {
        padding: 10px;
        font-size: 0.85rem;
    }

    .btn-calculate {
        padding: 11px;
        font-size: 0.9rem;
    }

    .result-summary {
        padding: 10px;
    }

    .result-header {
        font-size: 0.9rem;
    }

    .result-details {
        font-size: 0.85rem;
    }

    .stat-warning,
    .stat-success,
    .stat-neutral {
        padding: 8px;
        font-size: 0.85rem;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 10px;
    }

    .dashboard {
        padding: 10px;
    }

    .header {
        gap: 10px;
    }

    .user-info h2 {
        font-size: 1.1rem;
    }

    .semester-info {
        font-size: 0.8rem;
    }

    .stats-container {
        grid-template-columns: 1fr;
        gap: 8px;
    }

    .stat-card {
        padding: 12px;
    }

    .stat-icon {
        font-size: 1.8rem;
    }

    .stat-info h3 {
        font-size: 1.2rem;
    }

    .stat-info p {
        font-size: 0.75rem;
    }

    .section-title {
        font-size: 1.1rem;
    }

    .sort-controls label {
        font-size: 0.8rem;
    }

    .sort-select {
        font-size: 0.8rem;
        padding: 7px 10px;
    }

    .section-subtitle {
        font-size: 0.75rem;
    }

    .attendance-card {
        padding: 12px;
    }

    .course-code {
        font-size: 0.8rem;
    }

    .course-name {
        font-size: 0.9rem;
    }

    .attendance-badge {
        font-size: 1rem;
        padding: 5px 10px;
    }

    .course-stats {
        gap: 8px;
    }

    .stat-item {
        font-size: 0.8rem;
    }

    .status-box {
        padding: 8px;
        font-size: 0.8rem;
    }

    .predictor-box {
        padding: 10px;
    }

    .predictor-title {
        font-size: 0.8rem;
        margin-bottom: 10px;
    }

    .predictor-input-row {
        gap: 6px;
        margin-bottom: 8px;
    }

    .predictor-input-half {
        padding: 9px;
        font-size: 0.8rem;
    }

    .btn-calculate {
        padding: 10px;
        font-size: 0.85rem;
    }

    .calc-result {
        margin-top: 12px;
    }

    .result-summary {
        padding: 8px;
    }

    .result-header {
        font-size: 0.85rem;
        margin-bottom: 6px;
    }

    .result-details {
        font-size: 0.8rem;
    }

    .stat-warning,
    .stat-success,
    .stat-neutral {
        padding: 8px;
        font-size: 0.8rem;
        gap: 8px;
    }

    .stat-icon {
        font-size: 1rem;
    }

    .login-box {
        padding: 20px;
    }

    .logo h1 {
        font-size: 1.5rem;
    }

    .logo p {
        font-size: 0.9rem;
    }
}

.section-header {
    margin-bottom: 20px;
}

.header-top {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 15px;
    margin-bottom: 10px;
}

.section-title {
    margin: 0;
    font-size: 1.5rem;
    color: var(--text-primary);
}

.sort-controls {
    display: flex;
    align-items: center;
    gap: 10px;
}

.sort-controls label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    white-space: nowrap;
}

.sort-select {
    background: var(--bg-primary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
    padding: 8px 12px;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    cursor: pointer;
    transition: all 0.2s;
}

.sort-select:focus {
    outline: none;
    border-color: var(--accent-blue);
    box-shadow: 0 0 0 2px rgba(59, 130, 246, 0.2);
}

.sort-select:hover {
    border-color: var(--accent-blue);
}

.section-subtitle {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin: 0;
    font-style: italic;
}