:root {
    --bg: #0b1013;
    --bg-alt: #14191f;
    --card-bg: #181f25;
    --accent: #0097a7;
    --accent-soft: rgba(0, 151, 167, 0.14);
    --accent-alt: #00bcd4;
    --text: #f5f5f5;
    --muted: #9ca3af;
    --border: #2b2c36;
    --success: #10b981;
    --danger: #ef4444;
    --warning: #f59e0b;
    --info: #3b82f6;
    --radius-lg: 16px;
    --radius-xl: 22px;
    --shadow-soft: 0 18px 45px rgba(0,0,0,0.45);
    --font-main: 'Poppins', system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
}

*,
*::before,
*::after {
    box-sizing: border-box;
}

body {
    margin: 0;
    font-family: var(--font-main);
    background: radial-gradient(circle at top left, #1f2933 0, #050509 45%, #010101 100%);
    color: var(--text);
    min-height: 100vh;
}

/* Layout */
.main-header {
    position: sticky;
    top: 0;
    z-index: 40;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 7vw;
    backdrop-filter: blur(18px);
    background: linear-gradient(90deg, rgba(0,0,0,0.82), rgba(10,10,14,0.9));
    border-bottom: 1px solid rgba(148,163,184,0.25);
}

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

.logo-mark {
    width: 32px;
    height: 32px;
    border-radius: 14px;
    background: radial-gradient(circle at 30% 20%, #00bcd4, #6b7280);
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 10px 25px rgba(248,113,113,0.45);
}
.logo-mark i {
    color: white;
    font-size: 16px;
}

.logo-text {
    font-weight: 600;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    font-size: 0.9rem;
}

.main-nav {
    display: flex;
    gap: 18px;
    font-size: 0.9rem;
}

.main-nav a {
    color: var(--muted);
    text-decoration: none;
    padding: 6px 10px;
    border-radius: 999px;
    transition: all 0.2s ease;
}

.main-nav a:hover {
    color: white;
    background: rgba(148,163,184,0.18);
}

.main-content {
    padding: 32px 7vw 48px;
}

/* Hero */
.hero {
    display: grid;
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    gap: 36px;
    align-items: center;
}

.hero-text h1 {
    font-size: clamp(2.2rem, 3.4vw, 3rem);
    line-height: 1.1;
    margin-bottom: 12px;
}

.hero-text h1 span {
    background: linear-gradient(90deg, #4dd0e1, #26c6da, #b2ebf2);
    -webkit-background-clip: text;
    color: transparent;
}

.hero-text p {
    color: var(--muted);
    max-width: 540px;
    margin-bottom: 24px;
}

.hero-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
}

.hero-card {
    background: radial-gradient(circle at top left, rgba(0,188,212,0.16), transparent 55%),
                radial-gradient(circle at bottom right, rgba(55,65,81,0.9), #020617);
    border-radius: var(--radius-xl);
    padding: 18px 18px;
    border: 1px solid rgba(148,163,184,0.25);
    box-shadow: var(--shadow-soft);
}

.hero-card h2 {
    margin-top: 0;
}

.hero-visual {
    display: grid;
    gap: 16px;
}

.hero-metric {
    display: flex;
    flex-direction: column;
    gap: 4px;
}

.hero-metric i {
    font-size: 1.7rem;
    margin-bottom: 8px;
    color: #b2ebf2;
}

/* Buttons */
.btn {
    border: none;
    cursor: pointer;
    font-family: inherit;
    font-size: 0.95rem;
    border-radius: 999px;
    padding: 9px 18px;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    font-weight: 500;
    text-decoration: none;
    transition: transform 0.15s ease, box-shadow 0.15s ease, background 0.15s ease, color 0.15s ease, border-color 0.15s ease;
}

.btn.primary {
    background: linear-gradient(135deg, var(--accent), var(--accent-alt));
    color: white;
    box-shadow: 0 13px 30px rgba(0,150,167,0.55);
}

.btn.primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 18px 40px rgba(0,188,212,0.7);
}

.btn.ghost {
    background: transparent;
    border: 1px solid rgba(148,163,184,0.5);
    color: var(--muted);
}

.btn.ghost:hover {
    background: rgba(148,163,184,0.18);
    color: white;
}

.btn.full {
    width: 100%;
    justify-content: center;
}

.btn.small {
    padding: 4px 12px;
    font-size: 0.8rem;
}

.btn.success {
    background: rgba(16,185,129,0.1);
    color: #6ee7b7;
    border: 1px solid rgba(16,185,129,0.45);
}

.btn.danger {
    background: rgba(239,68,68,0.1);
    color: #b2ebf2;
    border: 1px solid rgba(239,68,68,0.6);
}

/* Auth */
.auth-section {
    display: flex;
    justify-content: center;
    padding-top: 32px;
}

.auth-card {
    width: 100%;
    max-width: 440px;
    background: radial-gradient(circle at top left, rgba(0,188,212,0.16), transparent 60%),
                linear-gradient(135deg, #020617, #020617);
    border-radius: var(--radius-xl);
    padding: 26px 24px 26px;
    border: 1px solid rgba(148,163,184,0.3);
    box-shadow: var(--shadow-soft);
}

.auth-card h1 {
    margin-top: 0;
    margin-bottom: 8px;
}

.auth-card p {
    margin-top: 0;
    margin-bottom: 18px;
    color: var(--muted);
    font-size: 0.9rem;
}

/* Form */
.form,
.form-inline {
    display: flex;
    flex-direction: column;
    gap: 14px;
}

.form-inline {
    flex-direction: row;
    flex-wrap: wrap;
    align-items: center;
}

.form-inline input {
    flex: 1 1 140px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 6px;
}

.form-group label {
    font-size: 0.82rem;
    color: var(--muted);
}

.form-group input,
.form-group select,
.form-group textarea,
.form-inline input {
    background: #020617;
    border-radius: 999px;
    border: 1px solid rgba(148,163,184,0.45);
    padding: 9px 13px;
    font-family: inherit;
    font-size: 0.9rem;
    color: var(--text);
    outline: none;
    transition: border-color 0.15s ease, box-shadow 0.15s ease, background 0.15s ease;
}

.form-group textarea {
    border-radius: 12px;
    min-height: 80px;
    resize: vertical;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus,
.form-inline input:focus {
    border-color: var(--accent-alt);
    box-shadow: 0 0 0 1px rgba(239,68,68,0.5);
    background: #020617;
}

.small-input {
    max-width: 200px;
    padding: 6px 10px;
    font-size: 0.8rem;
}

.form-grid-2 {
    display: grid;
    gap: 10px;
    grid-template-columns: repeat(2, minmax(0, 1fr));
}

.auth-switch {
    margin-top: 6px;
    font-size: 0.85rem;
    color: var(--muted);
}

.auth-switch a {
    color: #fca5a5;
    text-decoration: none;
}

/* Alerts */
.alert {
    padding: 8px 11px;
    border-radius: 999px;
    font-size: 0.8rem;
    display: flex;
    align-items: center;
    gap: 8px;
}

.alert.error {
    background: rgba(239,68,68,0.12);
    color: #b2ebf2;
    border: 1px solid rgba(239,68,68,0.6);
}

.alert.success {
    background: rgba(16,185,129,0.1);
    color: #bbf7d0;
    border: 1px solid rgba(16,185,129,0.55);
}

/* Badges */
.badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 10px;
    border-radius: 999px;
    font-size: 0.78rem;
    background: rgba(148,163,184,0.2);
}

.badge.pending {
    background: rgba(245,158,11,0.15);
    color: #fbbf24;
}

.badge.accepted {
    background: rgba(16,185,129,0.16);
    color: #6ee7b7;
}

.badge.rejected {
    background: rgba(239,68,68,0.18);
    color: #b2ebf2;
}

/* Quiz */
.quiz-section {
    display: flex;
    justify-content: center;
}

.quiz-card {
    width: 100%;
    max-width: 820px;
    background: radial-gradient(circle at top left, rgba(248,113,113,0.12), transparent 60%),
                radial-gradient(circle at bottom right, rgba(37,99,235,0.12), #020617);
    border-radius: var(--radius-xl);
    padding: 22px 22px 24px;
    border: 1px solid rgba(148,163,184,0.3);
    box-shadow: var(--shadow-soft);
}

.quiz-card h1 {
    margin-top: 0;
    margin-bottom: 6px;
}

.quiz-card > p {
    margin-top: 0;
    margin-bottom: 16px;
    color: var(--muted);
    font-size: 0.9rem;
}

.quiz-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 14px;
    margin-bottom: 12px;
}

.timer {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 6px 11px;
    border-radius: 999px;
    background: rgba(15,23,42,0.9);
    border: 1px solid rgba(0,188,212,0.7);
    font-size: 0.9rem;
}

.timer i {
    color: #b2ebf2;
}

.quiz-progress {
    flex: 1;
    height: 7px;
    border-radius: 999px;
    background: rgba(31,41,55,0.9);
    overflow: hidden;
}

.quiz-progress-bar {
    height: 100%;
    width: 0;
    border-radius: inherit;
    background: linear-gradient(90deg, #22c55e, #a3e635);
    transition: width 0.22s ease-out;
}

.quiz-questions {
    margin-top: 6px;
    margin-bottom: 14px;
    position: relative;
    min-height: 180px;
}

.question-card {
    display: none;
}

.question-card.active {
    display: block;
}

.question-header {
    display: flex;
    justify-content: space-between;
    font-size: 0.8rem;
    color: var(--muted);
    margin-bottom: 4px;
}

.question-text {
    margin-top: 0;
    margin-bottom: 10px;
    font-weight: 500;
}

.options {
    display: grid;
    gap: 8px;
}

.option {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 10px;
    border-radius: 999px;
    background: rgba(15,23,42,0.95);
    border: 1px solid rgba(148,163,184,0.35);
    cursor: pointer;
    font-size: 0.9rem;
}

.option-input {
    display: none;
}

.option-mark {
    width: 18px;
    height: 18px;
    border-radius: 999px;
    border: 2px solid rgba(148,163,184,0.7);
    flex-shrink: 0;
    position: relative;
}

.option-input:checked + .option-mark {
    border-color: #4dd0e1;
}

.option-input:checked + .option-mark::after {
    content: '';
    position: absolute;
    inset: 2px;
    border-radius: inherit;
    background: linear-gradient(135deg, #26c6da, #b2ebf2);
}

.option-input:checked + .option-mark + .option-text {
    color: #fee2e2;
}

.option-text {
    color: var(--muted);
}

.quiz-footer {
    display: flex;
    justify-content: space-between;
    gap: 10px;
}

/* Result */
.result-section {
    display: flex;
    justify-content: center;
}

.result-card {
    width: 100%;
    max-width: 520px;
    background: radial-gradient(circle at top left, rgba(52,211,153,0.18), transparent 60%),
                linear-gradient(145deg, #020617, #020617);
    border-radius: var(--radius-xl);
    padding: 22px 24px 24px;
    border: 1px solid rgba(74,222,128,0.4);
    box-shadow: var(--shadow-soft);
}

.result-card h1 {
    margin-top: 0;
    margin-bottom: 10px;
}

.result-stats {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
    margin-bottom: 12px;
}

.result-item {
    padding: 10px 12px;
    border-radius: 14px;
    background: rgba(15,23,42,0.95);
    border: 1px solid rgba(74,85,104,0.7);
}

.result-item .label {
    font-size: 0.75rem;
    color: var(--muted);
}

.result-item .value {
    font-size: 1.1rem;
    font-weight: 600;
}

.result-message {
    margin-top: 0;
    margin-bottom: 18px;
    color: var(--muted);
}

/* Admin layout */
.admin-body {
    background: radial-gradient(circle at top left, #1f2933 0, #020617 45%, #000 100%);
    margin: 0;
    font-family: var(--font-main);
    color: var(--text);
}

.admin-layout {
    display: grid;
    grid-template-columns: 250px minmax(0, 1fr);
    min-height: 100vh;
}

.admin-sidebar {
    background: linear-gradient(180deg, #020617, #050816);
    border-right: 1px solid rgba(30,64,175,0.45);
    padding: 18px 16px;
    display: flex;
    flex-direction: column;
    gap: 18px;
}

.admin-brand {
    display: flex;
    align-items: center;
    gap: 10px;
}

.admin-nav {
    display: flex;
    flex-direction: column;
    gap: 6px;
    font-size: 0.9rem;
}

.admin-nav a {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 8px 10px;
    border-radius: 999px;
    text-decoration: none;
    color: var(--muted);
    transition: background 0.16s ease, color 0.16s ease, transform 0.12s ease;
}

.admin-nav a:hover {
    background: rgba(30,64,175,0.28);
    color: white;
    transform: translateX(1px);
}

.admin-nav a.danger {
    margin-top: 6px;
    color: #b2ebf2;
}

.admin-main {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

.admin-header-bar {
    padding: 14px 20px;
    border-bottom: 1px solid rgba(30,64,175,0.4);
    backdrop-filter: blur(14px);
    background: linear-gradient(90deg, rgba(15,23,42,0.9), rgba(8,47,73,0.9));
}

.admin-header-bar h1 {
    margin: 0;
    font-size: 1.2rem;
}

.admin-main-content {
    padding: 18px 20px 26px;
}

/* Cards / tables */
.card {
    background: rgba(15,23,42,0.96);
    border-radius: var(--radius-lg);
    padding: 14px 16px 16px;
    border: 1px solid rgba(30,64,175,0.4);
    box-shadow: 0 14px 40px rgba(15,23,42,0.7);
    margin-bottom: 18px;
}

.card h2 {
    margin-top: 0;
    margin-bottom: 10px;
    font-size: 1rem;
}

.dashboard-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    gap: 12px;
    margin-bottom: 18px;
}

.stat-card {
    display: flex;
    gap: 12px;
    align-items: center;
    padding: 12px 13px;
    border-radius: 18px;
    background: radial-gradient(circle at top left, rgba(148,163,184,0.35), transparent 60%),
                rgba(15,23,42,0.96);
}

.stat-card .stat-icon {
    width: 38px;
    height: 38px;
    border-radius: 999px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: rgba(15,23,42,0.9);
}

.stat-card .stat-icon i {
    font-size: 1rem;
    color: #e0f7fa;
}

.stat-card.success {
    background: radial-gradient(circle at top left, rgba(16,185,129,0.3), transparent 60%),
                rgba(15,23,42,0.96);
}

.stat-card.danger {
    background: radial-gradient(circle at top left, rgba(244,143,177,0.32), transparent 60%),
                rgba(15,23,42,0.96);
}

.stat-card.warning {
    background: radial-gradient(circle at top left, rgba(245,158,11,0.32), transparent 60%),
                rgba(15,23,42,0.96);
}

.stat-card.info {
    background: radial-gradient(circle at top left, rgba(0,188,212,0.32), transparent 60%),
                rgba(15,23,42,0.96);
}

.stat-label {
    font-size: 0.78rem;
    color: var(--muted);
}

.stat-value {
    font-size: 1.2rem;
    font-weight: 600;
}

/* Tables */
.table-card {
    padding-top: 12px;
}

.table-wrapper {
    width: 100%;
    overflow-x: auto;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.82rem;
}

.data-table thead {
    background: rgba(15,23,42,0.98);
}

.data-table th,
.data-table td {
    text-align: left;
    padding: 7px 8px;
    border-bottom: 1px solid rgba(31,41,55,0.9);
}

.data-table tbody tr:hover {
    background: rgba(30,64,175,0.26);
    cursor: pointer;
}

.data-table tbody tr td.actions {
    white-space: nowrap;
}

.inline-form {
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

/* Student avatar fixed size */
.student-avatar {
    width: 48px;
    height: 48px;
    border-radius: 999px;
    background: radial-gradient(circle at top left, rgba(0,188,212,0.28), rgba(31,41,55,1));
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
    font-size: 1rem;
    color: #fee2e2;
    box-shadow: 0 10px 25px rgba(0,0,0,0.45);
}

.student-avatar.large {
    width: 72px;
    height: 72px;
    font-size: 1.4rem;
}

/* Modal */
.modal {
    position: fixed;
    inset: 0;
    background: rgba(15,23,42,0.78);
    display: none;
    align-items: center;
    justify-content: center;
    z-index: 70;
}

.modal.show {
    display: flex;
}

.modal-dialog {
    background: radial-gradient(circle at top left, rgba(248,113,113,0.18), transparent 60%),
                rgba(15,23,42,0.98);
    border-radius: 20px;
    padding: 18px 18px 18px;
    border: 1px solid rgba(0,188,212,0.7);
    width: 100%;
    max-width: 420px;
    position: relative;
    box-shadow: var(--shadow-soft);
}

.modal-close {
    border: none;
    background: transparent;
    color: var(--muted);
    position: absolute;
    right: 10px;
    top: 10px;
    cursor: pointer;
}

.modal-header {
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 10px;
}

.modal-header h3 {
    margin: 0;
}

.modal-body p {
    margin: 4px 0;
    font-size: 0.9rem;
}

.muted {
    color: var(--muted);
}

/* Footer */
.main-footer {
    padding: 14px 7vw 20px;
    border-top: 1px solid rgba(31,41,55,0.9);
    font-size: 0.78rem;
    color: var(--muted);
    text-align: center;
}

/* Responsive */
@media (max-width: 900px) {
    .hero {
        grid-template-columns: minmax(0,1fr);
    }
    .admin-layout {
        grid-template-columns: 1fr;
    }
    .admin-sidebar {
        position: sticky;
        top: 0;
        z-index: 50;
        flex-direction: row;
        align-items: center;
        justify-content: space-between;
    }
    .admin-nav {
        flex-direction: row;
        flex-wrap: wrap;
    }
    .admin-main-content {
        padding: 14px;
    }
    .auth-card,
    .quiz-card,
    .result-card {
        padding: 18px 16px 20px;
    }
    .result-stats {
        grid-template-columns: repeat(2,minmax(0,1fr));
    }
}


.logo-img {
    height: 40px;
    width: auto;
    object-fit: contain;
    filter: drop-shadow(0 6px 18px rgba(59,130,246,0.55));
}
.logo-text-group {
    display: flex;
    flex-direction: column;
    line-height: 1.1;
}
.logo-title {
    font-weight: 600;
    letter-spacing: 0.04em;
    text-transform: uppercase;
    font-size: 0.9rem;
}
.logo-subtitle {
    font-size: 0.7rem;
    color: var(--muted);
}