:root {
    --navy: #004467;
    --navy-dark: #00314a;
    --pink: #d91b5c;
    --purple: #8d50a0;
    --green: #056839;
    --light-green: #8cc63f;
    --brown: #764c29;
    --white: #ffffff;
    --yellow: #ffd402;
    --blue: #00aeef;
    --orange: #f7941d;
    --bg: #eef2f7;
    --text: #1f2937;
    --muted: #64748b;
    --border: #e3e8ef;
    --radius: 14px;
    --shadow: 0 6px 20px rgba(0,68,103,0.08);
    --shadow-lg: 0 24px 60px rgba(0,20,40,0.28);
}

* { box-sizing: border-box; }

body {
    margin: 0;
    font-family: 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
}

a { text-decoration: none; color: inherit; }
h1, h2, h3, h4 { font-family: inherit; }

/* ---------- Auth ---------- */
.auth-wrapper {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: radial-gradient(circle at 20% 20%, #00608f 0%, var(--navy) 45%, var(--navy-dark) 100%);
    padding: 20px;
    position: relative;
    overflow: hidden;
}

.auth-bg-shape {
    position: absolute;
    border-radius: 50%;
    opacity: 0.16;
    filter: blur(2px);
}
.shape-1 { width: 480px; height: 480px; background: var(--blue); top: -160px; left: -160px; }
.shape-2 { width: 380px; height: 380px; background: var(--pink); bottom: -140px; right: -120px; }

.auth-card {
    position: relative;
    z-index: 1;
    background: var(--white);
    border-radius: 20px;
    padding: 44px 40px;
    width: 100%;
    max-width: 420px;
    box-shadow: var(--shadow-lg);
    text-align: center;
}

.auth-card img.logo { width: 150px; margin-bottom: 18px; }
.auth-card .card-title { font-size: 19px; color: var(--navy); margin: 0 0 6px; }
.auth-card p.subtitle { font-size: 13px; color: var(--muted); margin-bottom: 22px; }
.auth-card .link-back { display: inline-block; margin-top: 18px; font-size: 13px; color: var(--blue); font-weight: 600; }

.form-group { margin-bottom: 16px; text-align: left; }
.form-group label { display: block; font-size: 13px; font-weight: 600; margin-bottom: 6px; color: var(--navy); }
.form-group input, .form-group select, .form-group textarea {
    width: 100%;
    padding: 11px 13px;
    border: 1.5px solid var(--border);
    border-radius: 10px;
    font-size: 14px;
    font-family: inherit;
    background: #fbfcfe;
    transition: border-color .15s, box-shadow .15s;
}
.form-group input:focus, .form-group select:focus, .form-group textarea:focus {
    outline: none;
    border-color: var(--blue);
    box-shadow: 0 0 0 3px rgba(0,174,239,0.15);
    background: var(--white);
}
.form-group .hint { font-size: 11px; color: var(--muted); margin-top: 4px; }
.form-row { display: grid; grid-template-columns: repeat(2, 1fr); gap: 14px; }
.form-row-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 14px; }
@media (max-width: 640px) { .form-row, .form-row-3 { grid-template-columns: 1fr; } }

.btn {
    display: inline-block;
    padding: 10px 20px;
    border-radius: 10px;
    border: none;
    background: linear-gradient(135deg, var(--navy), #006190);
    color: var(--white);
    font-weight: 600;
    cursor: pointer;
    font-size: 14px;
    transition: transform .12s, box-shadow .12s;
    box-shadow: 0 4px 12px rgba(0,68,103,0.25);
}
.btn:hover { transform: translateY(-1px); box-shadow: 0 6px 16px rgba(0,68,103,0.32); }
.btn:active { transform: translateY(0); }
.btn-block { width: 100%; }
.btn-lg { padding: 13px 20px; font-size: 15px; }
.btn-pink { background: linear-gradient(135deg, var(--pink), #b9154c); box-shadow: 0 4px 12px rgba(217,27,92,0.3); }
.btn-green { background: linear-gradient(135deg, var(--green), #044a29); box-shadow: 0 4px 12px rgba(5,104,57,0.3); }
.btn-purple { background: linear-gradient(135deg, var(--purple), #6e3c80); }
.btn-sm { padding: 7px 14px; font-size: 12px; border-radius: 8px; }
.btn-danger { background: linear-gradient(135deg, var(--pink), #a01049); }
.btn-outline { background: transparent; color: var(--navy); box-shadow: none; border: 1.5px solid var(--border); }
.btn-outline:hover { border-color: var(--navy); box-shadow: none; }

.alert {
    background: #fdeaea;
    color: var(--pink);
    border: 1px solid rgba(217,27,92,0.3);
    border-radius: 10px;
    padding: 11px 14px;
    font-size: 13px;
    margin-bottom: 16px;
    text-align: left;
}
.alert.success { background: #e8f7ee; color: var(--green); border-color: rgba(5,104,57,0.3); }

/* ---------- App Shell ---------- */
.app-shell { display: flex; min-height: 100vh; }

.sidebar {
    width: 252px;
    background: linear-gradient(195deg, var(--navy) 0%, var(--navy-dark) 100%);
    color: var(--white);
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
}

.sidebar .brand {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 26px 18px 20px;
}
.sidebar .brand img { width: 130px; }

.sidebar nav { padding: 6px 12px; flex: 1; }
.sidebar nav a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 14px;
    margin-bottom: 4px;
    font-size: 14px;
    font-weight: 500;
    color: rgba(255,255,255,0.78);
    border-radius: 10px;
    transition: background .15s, color .15s;
}
.sidebar nav a .icon { font-size: 16px; width: 20px; text-align: center; }
.sidebar nav a:hover { background: rgba(255,255,255,0.08); color: var(--white); }
.sidebar nav a.active { background: rgba(255,255,255,0.14); color: var(--white); box-shadow: inset 3px 0 0 var(--yellow); }

.topbar-profile { position: relative; flex-shrink: 0; }
.topbar-profile .profile-trigger {
    display: flex;
    align-items: center;
    gap: 10px;
    background: var(--bg);
    border: none;
    border-radius: 999px;
    padding: 6px 8px 6px 16px;
    cursor: pointer;
    color: var(--text);
    transition: background .15s;
}
.topbar-profile .profile-trigger:hover { background: #e6ecf3; }
.avatar {
    width: 38px;
    height: 38px;
    border-radius: 50%;
    background: var(--yellow);
    color: var(--navy);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 15px;
    flex-shrink: 0;
    overflow: hidden;
}
.avatar img { width: 100%; height: 100%; object-fit: cover; }
.topbar-profile .profile-meta { display: flex; flex-direction: column; align-items: flex-end; }
.topbar-profile .profile-name { font-size: 13px; font-weight: 700; color: var(--navy); white-space: nowrap; }
.topbar-profile .profile-role { font-size: 11px; color: var(--muted); }
.topbar-profile .chevron { font-size: 11px; color: var(--muted); transition: transform .15s; }
.topbar-profile.open .chevron { transform: rotate(180deg); }

.topbar-profile .profile-dropdown {
    display: none;
    position: absolute;
    top: calc(100% + 8px);
    right: 0;
    min-width: 190px;
    background: var(--white);
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    overflow: hidden;
    z-index: 30;
}
.topbar-profile.open .profile-dropdown { display: block; }
.topbar-profile .profile-dropdown a {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 16px;
    font-size: 13px;
    font-weight: 600;
    color: var(--navy);
}
.topbar-profile .profile-dropdown a:hover { background: var(--bg); }
.topbar-profile .profile-dropdown a:last-child { color: var(--pink); }

.main { flex: 1; display: flex; flex-direction: column; min-width: 0; }

.topbar {
    background: var(--white);
    padding: 18px 32px;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.topbar h2 { margin: 0; font-size: 19px; color: var(--navy); font-weight: 700; }

.content { padding: 30px 32px; flex: 1; }

/* ---------- Cards / Stats ---------- */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(190px, 1fr));
    gap: 18px;
    margin-bottom: 28px;
}
.stat-card {
    background: var(--white);
    border-radius: var(--radius);
    padding: 22px;
    box-shadow: var(--shadow);
    border-left: 5px solid var(--blue);
    display: flex;
    align-items: center;
    gap: 14px;
}
.stat-card .stat-icon {
    width: 46px; height: 46px;
    border-radius: 12px;
    display: flex; align-items: center; justify-content: center;
    font-size: 20px;
    background: rgba(0,174,239,0.12);
    flex-shrink: 0;
}
.stat-card.pink { border-left-color: var(--pink); }
.stat-card.pink .stat-icon { background: rgba(217,27,92,0.12); }
.stat-card.green { border-left-color: var(--green); }
.stat-card.green .stat-icon { background: rgba(5,104,57,0.12); }
.stat-card.purple { border-left-color: var(--purple); }
.stat-card.purple .stat-icon { background: rgba(141,80,160,0.12); }
.stat-card.orange { border-left-color: var(--orange); }
.stat-card.orange .stat-icon { background: rgba(247,148,29,0.14); }
.stat-card.blue { border-left-color: #2980b9; }
.stat-card.blue .stat-icon { background: rgba(41,128,185,0.12); }
.stat-card .num { font-size: 26px; font-weight: 700; color: var(--navy); line-height: 1; }
.stat-card .label { font-size: 12.5px; color: var(--muted); margin-top: 4px; }

.card {
    background: var(--white);
    border-radius: var(--radius);
    padding: 26px;
    box-shadow: var(--shadow);
    margin-bottom: 24px;
}
.card h3 { margin-top: 0; color: var(--navy); font-size: 16px; display: flex; align-items: center; gap: 8px; }
.card .card-desc { color: var(--muted); font-size: 13px; margin-top: -8px; margin-bottom: 18px; }

.link-back { font-size: 13px; color: var(--blue); font-weight: 600; display: inline-block; }
.link-back:hover { text-decoration: underline; }

.toolbar { display: flex; justify-content: space-between; align-items: center; margin-bottom: 18px; gap: 12px; flex-wrap: wrap; }

table { width: 100%; border-collapse: collapse; }
table th, table td { padding: 12px 14px; text-align: left; border-bottom: 1px solid var(--border); font-size: 13.5px; }
table th { color: var(--muted); font-weight: 700; font-size: 11.5px; text-transform: uppercase; letter-spacing: .03em; background: #f7f9fc; }
table tbody tr:hover { background: #f9fbfd; }
table.styled { border-radius: 10px; overflow: hidden; border: 1px solid var(--border); }

.badge { display: inline-block; padding: 4px 11px; border-radius: 999px; font-size: 12px; font-weight: 600; }
.badge.blue { background: rgba(0,174,239,0.12); color: var(--blue); }
.badge.pink { background: rgba(217,27,92,0.12); color: var(--pink); }
.badge.green { background: rgba(5,104,57,0.12); color: var(--green); }
.badge.purple { background: rgba(141,80,160,0.12); color: var(--purple); }
.badge.orange { background: rgba(247,148,29,0.14); color: var(--orange); }
.badge.gray { background: #eef1f5; color: var(--muted); }

.inline-form { display: inline; }

.table-avatar { width: 34px; height: 34px; border-radius: 50%; object-fit: cover; background: var(--bg); }
.table-name { display: flex; align-items: center; gap: 10px; font-weight: 600; color: var(--navy); }

.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 20px;
}
.video-card {
    background: var(--white);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
}
.video-card video { width: 100%; display: block; background: #000; }
.video-card .info { padding: 14px 16px; }
.video-card .info h4 { margin: 0 0 4px; color: var(--navy); font-size: 15px; }
.video-card .info p { margin: 0; font-size: 12px; color: var(--muted); }

.flex-row { display: flex; gap: 12px; flex-wrap: wrap; align-items: flex-end; }
.flex-row .form-group { flex: 1; min-width: 160px; margin-bottom: 0; }

.filter-bar { display: flex; gap: 10px; flex-wrap: wrap; margin-bottom: 18px; }
.filter-bar input, .filter-bar select {
    padding: 9px 12px;
    border: 1.5px solid var(--border);
    border-radius: 9px;
    font-size: 13px;
    background: #fbfcfe;
}

.assignment-card { border-left: 5px solid var(--purple); }
.assignment-card .assignment-desc { white-space: pre-line; color: var(--text); font-size: 13.5px; line-height: 1.6; margin: 10px 0; }

.assignment-item {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border-left: 5px solid var(--purple);
    margin-bottom: 16px;
    overflow: hidden;
}
.assignment-summary {
    list-style: none;
    cursor: pointer;
    padding: 18px 22px;
    display: flex;
    align-items: center;
    gap: 14px;
}
.assignment-summary::-webkit-details-marker { display: none; }
.assignment-toggle-icon {
    width: 38px; height: 38px;
    border-radius: 10px;
    background: rgba(141,80,160,0.12);
    display: flex; align-items: center; justify-content: center;
    font-size: 17px;
    flex-shrink: 0;
    transition: transform .2s;
}
.assignment-item[open] .assignment-toggle-icon { transform: rotate(-8deg) scale(1.05); }
.assignment-summary-text { flex: 1; min-width: 0; display: flex; flex-direction: column; gap: 4px; }
.assignment-summary-text strong { color: var(--navy); font-size: 15px; }
.assignment-meta { font-size: 12px; color: var(--muted); }
.assignment-status { flex-shrink: 0; }
.assignment-body { padding: 0 22px 22px; border-top: 1px solid var(--border); padding-top: 18px; }
.assignment-desc { white-space: pre-line; color: var(--text); font-size: 13.5px; line-height: 1.6; margin-bottom: 14px; }

.course-block {
    border: 1px solid var(--border);
    border-radius: 12px;
    margin-bottom: 14px;
    padding: 4px 18px;
    background: #fbfcfe;
}
.course-summary {
    list-style: none;
    cursor: pointer;
    padding: 14px 0;
    font-weight: 700;
    font-size: 15px;
    color: var(--navy);
}
.course-summary::-webkit-details-marker { display: none; }
.topic-block {
    border-left: 3px solid var(--blue);
    margin: 10px 0 14px 10px;
    padding-left: 16px;
}
.topic-summary {
    list-style: none;
    cursor: pointer;
    padding: 10px 0;
    font-weight: 600;
    font-size: 14px;
    color: var(--text);
    display: flex;
    align-items: center;
    gap: 10px;
}
.topic-summary::-webkit-details-marker { display: none; }

/* ---------- Modal ---------- */
.modal-overlay {
    display: none;
    position: fixed; inset: 0;
    background: rgba(0,20,40,0.55);
    z-index: 100;
    align-items: center;
    justify-content: center;
    padding: 24px;
}
.modal-overlay.open { display: flex; }
.modal-box {
    background: var(--white);
    border-radius: 18px;
    max-width: 560px;
    width: 100%;
    max-height: 88vh;
    overflow-y: auto;
    padding: 30px;
    box-shadow: var(--shadow-lg);
    position: relative;
}
.modal-close { position: absolute; top: 16px; right: 18px; cursor: pointer; font-size: 20px; color: var(--muted); border: none; background: none; }

.profile-header { display: flex; gap: 18px; align-items: center; margin-bottom: 20px; }
.avatar-lg { width: 84px; height: 84px; border-radius: 50%; object-fit: cover; background: var(--bg); border: 3px solid var(--border); display: block; }
.profile-header .avatar-lg { border-color: var(--bg); }
.profile-header h3 { margin: 0 0 4px; color: var(--navy); font-size: 18px; }
.profile-header p { margin: 0; color: var(--muted); font-size: 13px; }

.info-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 12px 20px; margin-top: 10px; }
.info-grid .info-item label { display: block; font-size: 11px; color: var(--muted); text-transform: uppercase; letter-spacing: .03em; margin-bottom: 2px; }
.info-grid .info-item span { font-size: 14px; font-weight: 600; color: var(--text); }

/* mobile sidebar: handled in responsive block below */

/* ---------- Print (A4 student card) ---------- */
@media print {
    body * { visibility: hidden; }
    .print-area, .print-area * { visibility: visible; }
    .print-area { position: absolute; top: 0; left: 0; width: 100%; }
}

/* ---------- Course Cards (Student dashboard) ---------- */
.course-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 18px;
    margin-bottom: 24px;
}
.course-card-link { text-decoration: none; color: inherit; display: block; }
.course-card {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    transition: transform .15s, box-shadow .15s;
    border-top: 4px solid var(--blue);
}
.course-card:hover { transform: translateY(-3px); box-shadow: 0 12px 32px rgba(0,68,103,0.14); }
.course-card-icon { font-size: 32px; flex-shrink: 0; }
.course-card-body { flex: 1; min-width: 0; }
.course-card-title { margin: 0 0 6px; font-size: 16px; color: var(--navy); font-weight: 700; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.course-card-meta { font-size: 12px; color: var(--muted); margin-bottom: 8px; display: flex; gap: 10px; }
.course-card-arrow { font-size: 20px; color: var(--muted); flex-shrink: 0; transition: transform .15s; }
.course-card-link:hover .course-card-arrow { transform: translateX(4px); color: var(--navy); }
.progress-bar-wrap { background: var(--border); border-radius: 999px; height: 6px; overflow: hidden; }
.progress-bar-fill { background: linear-gradient(90deg, var(--blue), var(--light-green)); height: 100%; border-radius: 999px; transition: width .4s; }

/* ---------- Udemy-like course detail ---------- */
.udemy-layout { display: flex; gap: 24px; align-items: flex-start; }
.udemy-sidebar {
    width: 280px;
    flex-shrink: 0;
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 16px;
    position: sticky;
    top: 20px;
}
.udemy-sidebar-header { display: flex; align-items: center; justify-content: space-between; margin-bottom: 10px; }
.udemy-toc { display: flex; flex-direction: column; gap: 2px; }
.udemy-toc-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 9px 10px;
    border-radius: 8px;
    font-size: 13px;
    color: var(--text);
    transition: background .12s;
    text-decoration: none;
}
.udemy-toc-item:hover { background: var(--bg); color: var(--navy); }
.udemy-toc-num { width: 22px; height: 22px; border-radius: 50%; background: var(--bg); display: flex; align-items: center; justify-content: center; font-size: 11px; font-weight: 700; color: var(--navy); flex-shrink: 0; }
.udemy-toc-label { flex: 1; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.udemy-main { flex: 1; min-width: 0; }

.udemy-topic {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    margin-bottom: 12px;
    overflow: hidden;
}
.udemy-topic-summary {
    list-style: none;
    cursor: pointer;
    padding: 16px 20px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
    user-select: none;
}
.udemy-topic-summary::-webkit-details-marker { display: none; }
.udemy-topic-left { display: flex; align-items: center; gap: 10px; }
.udemy-topic-chevron { display: inline-block; transition: transform .2s; font-size: 11px; color: var(--muted); }
.udemy-topic-title { font-size: 15px; font-weight: 700; color: var(--navy); }
.udemy-topic-right { flex-shrink: 0; }
.udemy-video-list { border-top: 1px solid var(--border); }
.udemy-video-item { border-bottom: 1px solid var(--border); padding: 16px 20px; }
.udemy-video-item:last-child { border-bottom: none; }
.udemy-video-header { display: flex; align-items: center; gap: 10px; margin-bottom: 14px; }
.udemy-video-play {
    width: 28px; height: 28px; border-radius: 50%;
    background: var(--blue); color: #fff;
    display: flex; align-items: center; justify-content: center;
    font-size: 11px; flex-shrink: 0;
    transition: background .15s;
}
.udemy-video-play.watched { background: var(--green); }
.udemy-video-title { font-weight: 600; font-size: 14px; color: var(--navy); }
.udemy-video-player { background: #000; border-radius: 10px; overflow: hidden; }

@media (max-width: 900px) {
    .udemy-layout { flex-direction: column; }
    .udemy-sidebar { width: 100%; position: static; }
}

/* ---------- Class Cards (Teacher upload) ---------- */
.class-card-link { text-decoration: none; color: inherit; display: block; }
.class-card {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 28px 22px;
    text-align: center;
    transition: transform .15s, box-shadow .15s;
    border-top: 4px solid var(--navy);
    cursor: pointer;
}
.class-card:hover { transform: translateY(-4px); box-shadow: 0 14px 36px rgba(0,68,103,0.16); border-top-color: var(--pink); }
.class-card-icon { font-size: 36px; margin-bottom: 12px; }
.class-card-name { font-size: 18px; font-weight: 700; color: var(--navy); margin-bottom: 10px; }
.class-card-meta { display: flex; gap: 6px; justify-content: center; margin-bottom: 12px; }
.class-card-action { font-size: 13px; color: var(--blue); font-weight: 600; }

/* ---------- Topic card rows (Teacher upload-topics) ---------- */
.topic-cards { display: flex; flex-direction: column; gap: 10px; }
.topic-card-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 18px;
    background: var(--bg);
    border-radius: 10px;
    border-left: 4px solid var(--purple);
    gap: 14px;
}
.topic-card-info { flex: 1; }

/* ---------- Uploaded video list ---------- */
.uploaded-video-list { display: flex; flex-direction: column; gap: 8px; }
.uploaded-video-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px 14px;
    background: var(--bg);
    border-radius: 8px;
}
.uploaded-video-icon { font-size: 20px; }
.uploaded-video-info { flex: 1; display: flex; justify-content: space-between; align-items: center; }

/* ---------- Messages ---------- */
.msg-toolbar { display: flex; align-items: center; justify-content: space-between; margin-bottom: 18px; flex-wrap: wrap; gap: 10px; }
.tab-pills { display: flex; gap: 6px; }
.tab-pill {
    padding: 8px 18px;
    border-radius: 999px;
    font-size: 13px;
    font-weight: 600;
    color: var(--muted);
    background: var(--white);
    border: 1.5px solid var(--border);
    transition: all .15s;
    text-decoration: none;
}
.tab-pill.active, .tab-pill:hover { background: var(--navy); color: #fff; border-color: var(--navy); }
.msg-table .msg-unread td { background: rgba(0,174,239,0.05); font-weight: 600; }
.msg-header { display: flex; justify-content: space-between; align-items: flex-start; gap: 16px; margin-bottom: 8px; flex-wrap: wrap; }
.msg-body { font-size: 15px; line-height: 1.7; color: var(--text); white-space: pre-wrap; }

/* ---------- Nav accordion ---------- */
.nav-accordion-toggle {
    display: flex;
    align-items: center;
    gap: 10px;
    width: 100%;
    background: none;
    border: none;
    cursor: pointer;
    color: rgba(255,255,255,0.72);
    font-size: 13.5px;
    font-weight: 500;
    padding: 10px 12px;
    border-radius: 10px;
    transition: background .15s, color .15s;
    text-align: left;
    text-decoration: none;
    font-family: inherit;
    letter-spacing: inherit;
}
.nav-accordion-toggle:hover { background: rgba(255,255,255,0.08); color: #fff; }
.nav-accordion-toggle .icon { font-size: 16px; width: 20px; text-align: center; flex-shrink: 0; }
.nav-accordion-toggle .label { flex: 1; }
.nav-accordion-toggle .nav-acc-arrow { font-size: 11px; opacity: .6; transition: transform .2s; }
.nav-accordion-toggle[aria-expanded="true"] .nav-acc-arrow { transform: rotate(180deg); }
.nav-accordion-body { padding-left: 8px; }
.nav-accordion-body a { padding-left: 32px !important; }
/* nav accordion mobile: handled in responsive block below */

/* ---------- Nav unread badge ---------- */
.nav-badge-wrap { position: relative; }
.nav-unread {
    position: absolute;
    top: 6px; right: 6px;
    background: var(--pink);
    color: #fff;
    font-size: 10px;
    font-weight: 700;
    border-radius: 999px;
    min-width: 16px;
    height: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0 4px;
}

/* ---------- Admin dashboard grid ---------- */
.dashboard-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 20px; margin-bottom: 24px; }
@media (max-width: 900px) { .dashboard-grid { grid-template-columns: 1fr; } }

.admin-quicklinks {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    gap: 12px;
    margin-bottom: 24px;
}
.quicklink-card {
    background: var(--white);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 18px 14px;
    text-align: center;
    text-decoration: none;
    color: var(--navy);
    transition: transform .15s, box-shadow .15s;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 8px;
}
.quicklink-card:hover { transform: translateY(-3px); box-shadow: 0 10px 28px rgba(0,68,103,0.14); }
.ql-icon { font-size: 28px; }
.ql-label { font-size: 13px; font-weight: 600; }

.recent-list { display: flex; flex-direction: column; gap: 10px; }
.recent-item { display: flex; align-items: center; gap: 12px; padding: 8px 0; border-bottom: 1px solid var(--border); }
.recent-item:last-child { border-bottom: none; }
.recent-icon { width: 36px; height: 36px; border-radius: 10px; display: flex; align-items: center; justify-content: center; font-size: 16px; flex-shrink: 0; }
.recent-info { flex: 1; min-width: 0; }
.recent-name { font-size: 14px; font-weight: 600; color: var(--navy); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.recent-sub { font-size: 12px; color: var(--muted); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }
.recent-date { font-size: 12px; color: var(--muted); flex-shrink: 0; }

/* ---------- Admin Video Cards ---------- */
.admin-video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 14px;
}
.admin-video-card {
    background: var(--bg);
    border-radius: 10px;
    overflow: hidden;
    border: 1px solid var(--border);
    transition: box-shadow .15s, transform .15s;
}
.admin-video-card:hover { box-shadow: var(--shadow); transform: translateY(-2px); }
.admin-video-thumb {
    position: relative;
    height: 110px;
    background: #111;
    overflow: hidden;
}
.admin-video-thumb video { width: 100%; height: 100%; object-fit: cover; }
.admin-video-play-icon {
    position: absolute;
    inset: 0;
    display: flex; align-items: center; justify-content: center;
    font-size: 22px;
    color: rgba(255,255,255,0.7);
    background: rgba(0,0,0,0.2);
    pointer-events: none;
}
.admin-video-info { padding: 10px 12px; }
.admin-video-title { font-size: 13px; font-weight: 600; color: var(--navy); white-space: nowrap; overflow: hidden; text-overflow: ellipsis; margin-bottom: 4px; }
.admin-video-meta { display: flex; flex-direction: column; gap: 2px; margin-bottom: 6px; }

/* ====== Admin Video Page ====== */
.video-filter-bar { display:flex; gap:8px; flex-wrap:wrap; margin-bottom:20px; }
.vf-tab { display:inline-flex; align-items:center; gap:6px; padding:8px 16px; border-radius:20px; font-size:13px; font-weight:600; background:#fff; border:1.5px solid var(--border); color:var(--navy); text-decoration:none; transition:all .18s; }
.vf-tab:hover { border-color:var(--blue); color:var(--blue); }
.vf-tab.active { background:var(--navy); color:#fff; border-color:var(--navy); }
.vf-count { font-size:11px; background:rgba(255,255,255,.25); border-radius:10px; padding:1px 6px; }
.vf-tab.active .vf-count { background:rgba(255,255,255,.2); }
.vcard-section { padding:0 !important; overflow:hidden; }
.vcard-class-header { display:flex; align-items:center; gap:10px; padding:16px 20px; background:linear-gradient(135deg,var(--navy),var(--navy-dark)); color:#fff; border-radius:var(--radius) var(--radius) 0 0; }
.vcard-class-icon { font-size:20px; }
.vcard-class-name { font-size:16px; font-weight:700; }
.vcard-teacher-block { border-bottom:1px solid var(--border); padding:0 20px 0; }
.vcard-teacher-block:last-child { border-bottom:none; }
.vcard-teacher-header { display:flex; align-items:center; gap:10px; padding:14px 0 10px; }
.vcard-teacher-avatar { width:36px; height:36px; border-radius:50%; background:var(--border); display:flex; align-items:center; justify-content:center; font-size:18px; flex-shrink:0; }
.vcard-teacher-name { font-weight:700; color:var(--navy); font-size:14px; }
.vcard-teacher-sub { font-size:11px; color:var(--muted); }
.vcard-course-details { margin-bottom:10px; border:1px solid var(--border); border-radius:10px; overflow:hidden; }
.vcard-course-summary { cursor:pointer; padding:10px 14px; font-weight:700; color:var(--navy); display:flex; align-items:center; gap:8px; list-style:none; background:#f8fafc; }
.vcard-course-summary:hover { background:#f0f4f8; }
.vcard-topic-list { padding:10px 14px 14px; }
.vcard-topic-row { margin-bottom:12px; }
.vcard-topic-label { font-size:12px; font-weight:700; color:var(--muted); text-transform:uppercase; letter-spacing:.04em; margin-bottom:6px; display:flex; align-items:center; gap:6px; }
.vcard-video-table-wrap { overflow-x:auto; }
.vcard-video-table { width:100%; border-collapse:collapse; font-size:13px; }
.vcard-video-table th { text-align:left; padding:6px 10px; font-size:11px; font-weight:700; color:var(--muted); text-transform:uppercase; letter-spacing:.04em; border-bottom:1px solid var(--border); background:#f8fafc; }
.vcard-video-row { border-bottom:1px solid var(--border); transition:background .15s; }
.vcard-video-row:last-child { border-bottom:none; }
.vcard-video-row:hover { background:#f5f8fc; }
.vcard-video-row td { padding:8px 10px; vertical-align:middle; }
.vcard-video-title-cell { display:flex; align-items:center; gap:10px; font-weight:500; }
.vcard-play-thumb { width:56px; height:36px; border-radius:6px; overflow:hidden; position:relative; background:#111; flex-shrink:0; cursor:pointer; }
.vcard-play-overlay { position:absolute; inset:0; display:flex; align-items:center; justify-content:center; color:#fff; font-size:13px; background:rgba(0,0,0,.35); pointer-events:none; }

/* ====== Compose Multi-Recipient ====== */
.recipient-box { border:1.5px solid var(--border); border-radius:10px; max-height:260px; overflow-y:auto; background:#fafbfc; }
.recipient-group { border-bottom:1px solid var(--border); }
.recipient-group:last-child { border-bottom:none; }
.recipient-group-header { padding:8px 12px; background:#f0f4f8; position:sticky; top:0; z-index:1; }
.recipient-check-all { display:flex; align-items:center; gap:8px; font-weight:700; color:var(--navy); font-size:13px; cursor:pointer; }
.recipient-items { padding:6px 0; }
.recipient-item { display:flex; align-items:center; gap:8px; padding:5px 16px; cursor:pointer; font-size:13px; transition:background .15s; }
.recipient-item:hover { background:#e8f0f8; }
.recipient-item input[type=checkbox] { width:15px; height:15px; accent-color:var(--navy); flex-shrink:0; }
.recipient-name { flex:1; color:var(--text); }
.recipient-selected-info { margin-top:6px; font-size:12px; color:var(--muted); padding:4px 0; }
.recipient-selected-info.has-selection { color:var(--green); font-weight:600; }

/* ====== Mesaj Başarı Toast ====== */
.msg-success-toast { position:fixed; top:24px; right:24px; z-index:9999; animation:toastIn .3s ease; }
.msg-success-toast.hiding { animation:toastOut .4s ease forwards; }
@keyframes toastIn { from{opacity:0;transform:translateY(-16px)} to{opacity:1;transform:translateY(0)} }
@keyframes toastOut { from{opacity:1;transform:translateY(0)} to{opacity:0;transform:translateY(-16px)} }
.msg-toast-inner { display:flex; align-items:center; gap:14px; background:#fff; border-radius:14px; box-shadow:0 8px 32px rgba(0,0,0,.16); padding:16px 20px; min-width:280px; border-left:4px solid #22c55e; }
.msg-toast-icon { width:38px; height:38px; border-radius:50%; background:#22c55e; color:#fff; display:flex; align-items:center; justify-content:center; font-size:20px; font-weight:700; flex-shrink:0; }
.msg-toast-title { font-weight:700; color:var(--navy); font-size:14px; }
.msg-toast-sub { font-size:12px; color:var(--muted); margin-top:2px; }
.msg-toast-close { margin-left:auto; background:none; border:none; cursor:pointer; font-size:16px; color:var(--muted); padding:4px; border-radius:4px; line-height:1; }
.msg-toast-close:hover { color:var(--text); }

/* ====== Teacher Video List (upload-content) ====== */
.teacher-video-list { display:flex; flex-direction:column; gap:10px; }
.teacher-video-row { display:flex; align-items:center; gap:14px; padding:10px 12px; border:1px solid var(--border); border-radius:10px; transition:background .15s; }
.teacher-video-row:hover { background:#f5f8fc; }
.teacher-video-thumb { width:72px; height:46px; border-radius:8px; overflow:hidden; position:relative; background:#111; flex-shrink:0; cursor:pointer; }
.teacher-video-play-btn { position:absolute; inset:0; display:flex; align-items:center; justify-content:center; color:#fff; font-size:16px; background:rgba(0,0,0,.38); pointer-events:none; }
.teacher-video-meta { flex:1; min-width:0; }
.teacher-video-title { font-weight:600; font-size:14px; color:var(--navy); white-space:nowrap; overflow:hidden; text-overflow:ellipsis; }
.teacher-video-date { font-size:12px; color:var(--muted); margin-top:2px; }

/* ====== Pagination ====== */
.pagination { display:flex; align-items:center; gap:6px; margin-top:20px; flex-wrap:wrap; }
.page-btn { display:inline-flex; align-items:center; justify-content:center; min-width:36px; height:36px; padding:0 10px; border-radius:8px; border:1.5px solid var(--border); background:#fff; color:var(--navy); font-size:13px; font-weight:600; text-decoration:none; transition:all .15s; }
.page-btn:hover { border-color:var(--navy); background:var(--navy); color:#fff; }
.page-btn.active { background:var(--navy); color:#fff; border-color:var(--navy); }

/* ====== Sidebar Contact Block ====== */
.sidebar-contact {
    margin:auto 12px 12px;
    background:rgba(255,255,255,.08);
    border:1px solid rgba(255,255,255,.15);
    border-radius:12px;
    padding:12px;
}
.sc-address {
    font-size:11px;
    color:rgba(255,255,255,.75);
    line-height:1.4;
    margin-bottom:10px;
}
.sc-links { display:flex; flex-direction:column; gap:6px; }
.sc-btn {
    display:flex; align-items:center; gap:8px;
    padding:7px 10px; border-radius:8px;
    font-size:12px; font-weight:600;
    color:#fff; text-decoration:none;
    transition:opacity .15s, transform .15s;
}
.sc-btn:hover { opacity:.88; transform:translateX(2px); }
.sc-wa { background:#25d366; }
.sc-ig { background:linear-gradient(135deg,#f58529,#dd2a7b,#515bd4); }
@media (max-width:768px) {
    .sidebar-contact { display:none; }
}

/* ====== Extra Fields (teacher/student form) ====== */
.extra-field-row { display:flex; gap:10px; align-items:flex-start; padding:10px 12px; border:1.5px solid var(--border); border-radius:10px; background:#fafbfc; }
.extra-field-row .ef-label { width:180px; flex-shrink:0; }
.extra-field-row .ef-value { flex:1; }
.extra-field-row .ef-remove { background:none; border:none; color:var(--muted); font-size:18px; cursor:pointer; padding:4px 6px; line-height:1; border-radius:6px; margin-top:4px; }
.extra-field-row .ef-remove:hover { color:#ef4444; background:#fee2e2; }


/* ============================================================
   RESPONSIVE — Mobile & Tablet
   Breakpoints: 480px (phone), 768px (tablet), 1024px (small laptop)
   ============================================================ */

/* ── Hamburger Button ── */
.hamburger-btn {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 6px;
    border-radius: 8px;
    flex-shrink: 0;
}
.hamburger-btn span {
    display: block;
    width: 22px;
    height: 2px;
    background: var(--navy);
    border-radius: 2px;
    transition: all .25s;
}
.hamburger-btn.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.hamburger-btn.open span:nth-child(2) { opacity: 0; }
.hamburger-btn.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Sidebar overlay (mobile) */
.sidebar-overlay {
    display: none;
    position: fixed;
    inset: 0;
    background: rgba(0,20,40,.5);
    z-index: 199;
}
.sidebar-overlay.active { display: block; }

/* ── Tablet (769px – 1024px): icon-only sidebar ── */
/* ── Tablet with labels (iPad 10 = 820px, iPad Air = 820px, iPad Pro 11 = 834px) ── */
@media (min-width: 769px) and (max-width: 1024px) {
    .topbar { padding: 12px 20px; }
    .content { padding: 18px; }
    .stats-grid { grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 12px; }
    .dashboard-grid { gap: 14px; }
    .form-row { grid-template-columns: repeat(2, 1fr); gap: 12px; }
    .info-grid { grid-template-columns: 1fr 1fr; }
    .card { padding: 18px; }
    .topbar h2 { font-size: 16px; }
    /* Sidebar narrower but labels visible */
    .sidebar { width: 200px; }
    .sidebar .brand img { width: 100px; }
    .sidebar nav a { font-size: 13px; padding: 8px 14px; }
    .hamburger-btn { display: none; }
    .sidebar-contact { display: none; }
}

/* Global: tables always scroll horizontally on narrow screens */
@media (max-width: 900px) {
    .card { overflow-x: auto; }
    .card > table, .card > .table-wrap > table { min-width: 500px; }
}

/* ── Mobile (≤ 768px) ── */
@media (max-width: 768px) {
    /* Hamburger visible */
    .hamburger-btn { display: flex; }

    /* Sidebar: slide-in drawer */
    .sidebar {
        position: fixed;
        top: 0; left: 0;
        height: 100%;
        width: 260px !important;
        z-index: 200;
        transform: translateX(-100%);
        transition: transform .28s cubic-bezier(.4,0,.2,1);
        overflow-y: auto;
    }
    .sidebar.open { transform: translateX(0); }
    .sidebar .brand img { width: 110px !important; }
    .sidebar nav a .label { display: flex !important; }
    .profile-meta { display: flex !important; }
    .chevron { display: block !important; }
    .nav-accordion-toggle .label,
    .nav-accordion-toggle .nav-acc-arrow { display: block !important; }
    .nav-accordion-toggle { justify-content: flex-start !important; }
    .nav-accordion-body a { padding-left: 32px !important; }
    .nav-accordion-body a .label { display: flex !important; }
    .sidebar-contact { display: none; }

    /* Main expands full width */
    .main { width: 100%; }

    /* Topbar */
    .topbar { padding: 12px 16px; }
    .topbar h2 { font-size: 15px; }
    .profile-meta { display: none !important; }
    .chevron { display: none !important; }
    .topbar-profile .profile-trigger { padding: 4px 6px 4px 10px; gap: 6px; }

    /* Content */
    .content { padding: 14px; }

    /* Cards */
    .card { padding: 16px; margin-bottom: 16px; }
    .card h3 { font-size: 15px; }

    /* Stats */
    .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 10px; margin-bottom: 16px; }
    .stat-card { padding: 14px; gap: 10px; }
    .stat-card .num { font-size: 22px; }
    .stat-card .stat-icon { width: 38px; height: 38px; font-size: 17px; }

    /* Dashboard grid */
    .dashboard-grid { grid-template-columns: 1fr; gap: 14px; }

    /* Quicklinks */
    .admin-quicklinks { grid-template-columns: repeat(3, 1fr); gap: 8px; }
    .quicklink-card { padding: 12px 8px; gap: 6px; }
    .ql-icon { font-size: 22px; }
    .ql-label { font-size: 11px; }

    /* Forms */
    .form-row, .form-row-3 { grid-template-columns: 1fr; gap: 10px; }
    .info-grid { grid-template-columns: 1fr; gap: 8px; }
    .flex-row { flex-direction: column; align-items: stretch; }
    .flex-row .form-group { min-width: 0; }
    .filter-bar { gap: 6px; }
    .filter-bar input, .filter-bar select { width: 100%; }

    /* Tables — horizontal scroll */
    .table-responsive { overflow-x: auto; -webkit-overflow-scrolling: touch; }
    table { min-width: 500px; }
    table.styled { min-width: 500px; }
    table th, table td { padding: 9px 10px; font-size: 12.5px; white-space: nowrap; }

    /* Toolbar */
    .toolbar { flex-direction: column; align-items: stretch; gap: 8px; }
    .toolbar .btn { width: 100%; text-align: center; }

    /* Buttons */
    .btn { font-size: 13px; padding: 9px 16px; }
    .btn-sm { font-size: 11px; padding: 5px 10px; }

    /* Profile header */
    .profile-header { flex-direction: column; text-align: center; gap: 12px; }
    .avatar-lg { width: 70px; height: 70px; }

    /* Modals */
    .modal-box { padding: 20px; margin: 10px; max-height: 92vh; }

    /* Video grid */
    .video-grid { grid-template-columns: 1fr; }
    .admin-video-grid { grid-template-columns: repeat(2, 1fr); gap: 10px; }

    /* Course cards */
    .course-cards { grid-template-columns: 1fr; gap: 12px; }

    /* Udemy layout */
    .udemy-layout { flex-direction: column; gap: 14px; }
    .udemy-sidebar { width: 100%; position: static; }

    /* Extra fields */
    .extra-field-row { flex-direction: column; }
    .extra-field-row .ef-label { width: 100%; }

    /* Messages */
    .tab-pills { flex-wrap: wrap; gap: 4px; }
    .tab-pill { padding: 6px 12px; font-size: 12px; }

    /* Pagination */
    .pagination { gap: 4px; }
    .page-btn { min-width: 32px; height: 32px; font-size: 12px; }

    /* Teacher video row */
    .teacher-video-row { flex-wrap: wrap; }
    .teacher-video-thumb { width: 60px; height: 38px; }

    /* Topic card row */
    .topic-card-row { flex-wrap: wrap; gap: 8px; }

    /* Exam group action buttons */
    .btn-group-mobile { flex-direction: column; gap: 6px; }

    /* Toast */
    #globalToast { bottom: 16px; right: 16px; left: 16px; max-width: none; font-size: 13px; padding: 12px 16px; }
}

/* ── Small phone (≤ 480px) ── */
@media (max-width: 480px) {
    .topbar { padding: 10px 12px; }
    .content { padding: 10px; }
    .card { padding: 14px; border-radius: 10px; }
    .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 8px; }
    .stat-card { padding: 12px 10px; }
    .stat-card .num { font-size: 20px; }
    .admin-quicklinks { grid-template-columns: repeat(2, 1fr); }
    .admin-video-grid { grid-template-columns: 1fr; }
    .auth-card { padding: 28px 20px; }
    .modal-box { padding: 16px; }
    .profile-trigger .profile-meta { display: none !important; }
    .topbar h2 { font-size: 14px; }
    table th, table td { padding: 7px 8px; font-size: 12px; }
}

/* ── Sidebar contact tablet (768–1024) ── */
/* sidebar-contact tablet margin handled in main tablet block above */

/* ============================================================
   EXAM PAGES — Mobile fixes
   ============================================================ */

/* 2-col grids (result view / entry charts) collapse on mobile */
.result-grid-2col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 16px;
}
@media (max-width: 768px) {
    .result-grid-2col { grid-template-columns: 1fr; }

    /* Score entry inputs: bigger touch target */
    .score-inp { width: 56px !important; font-size: 15px !important; padding: 6px 4px !important; }

    /* Student table action buttons: stack vertically */
    .exam-action-btns { flex-direction: column !important; gap: 5px !important; }
    .exam-action-btns .btn { width: 100%; text-align: center; }

    /* Exam tab panels need scroll */
    .exam-tab-panel { overflow-x: auto; -webkit-overflow-scrolling: touch; }

    /* Card overflow:hidden blocks table scroll — override for exam cards */
    .exam-student-card { overflow: visible !important; }
    .exam-student-card .exam-tab-panel { overflow-x: auto; }

    /* Exam groups list card */
    .exam-list-card { overflow-x: auto !important; }

    /* Teacher permissions table */
    .exam-perm-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }

    /* Score entry table */
    .score-table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; }
    .score-table-wrap table { min-width: 380px; }
}

/* ── Generic responsive 2-col grid ── */
.grid-2col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
}
.grid-2col-sm {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 4px 24px;
}
@media (max-width: 600px) {
    .grid-2col { grid-template-columns: 1fr; }
    .grid-2col-sm { grid-template-columns: 1fr; gap: 4px 0; }
    .result-grid-2col { grid-template-columns: 1fr; }
}

/* Misc mobile fixes */
@media (max-width: 768px) {
    /* student/teacher detail page: info cards side by side → stack */
    .detail-2col { flex-direction: column !important; }

    /* Teacher exam groups list */
    .teacher-exam-list-card { overflow-x: auto !important; }

    /* videos page */
    .admin-video-grid { grid-template-columns: repeat(2, 1fr) !important; }

    /* messages */
    .msg-compose-row { flex-direction: column !important; }

    /* leaderboard table */
    .leaderboard-card { overflow-x: auto; }

    /* assignment detail */
    .assignment-detail-grid { flex-direction: column !important; }

    /* analytics */
    .analytics-grid { flex-direction: column !important; }
}
@media (max-width: 480px) {
    .admin-video-grid { grid-template-columns: 1fr !important; }
    .grid-2col { grid-template-columns: 1fr; }
}

/* ── Global: all cards with overflow:hidden that contain tables get scroll on mobile ── */
@media (max-width: 900px) {
    /* exam-list-card and teacher-exam-list-card already have overflow-x:auto from .exam-list-card rule */
    /* additional pattern: any .card > table direct child */
    .card > table.styled,
    .card > div > table.styled { min-width: 500px; }
}