:root {
    --primary: #6B2D8E;
    --primary-dark: #4A1F63;
    --secondary: #C9A227;
    --accent: #B8860B;
    --danger: #c01c28;
    --success: #2e7d32;
    --bg: #FAF8FB;
    --card: #ffffff;
    --text: #1c1c1c;
    --text-muted: #5e5e5e;
    --border: #E8D5F2;
    --shadow: 0 2px 8px rgba(107,45,142,0.08);
    --shadow-lg: 0 8px 24px rgba(107,45,142,0.15);
}

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

body {
    font-family: "PingFang SC", "Microsoft YaHei", sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    min-height: 100vh;
}

.header {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: white;
    padding: 20px 32px;
    border-bottom: 3px solid var(--secondary);
}

.header-inner {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 20px;
    max-width: 900px;
    margin: 0 auto;
}

.header-text { text-align: left; }

.header h1 { font-size: 24px; font-weight: 700; }
.header p { opacity: 0.9; font-size: 13px; margin-top: 6px; }

@media (max-width: 600px) {
    .header-inner { flex-direction: column; gap: 10px; }
    .header-text { text-align: center; }
    .header h1 { font-size: 18px; }
}

.main { max-width: 960px; margin: 0 auto; padding: 24px; }

.card {
    background: var(--card);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 20px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
}

.card h2 {
    font-size: 18px;
    color: var(--primary);
    margin-bottom: 16px;
    padding-bottom: 10px;
    border-bottom: 2px solid var(--border);
}

.card h3 { font-size: 16px; color: var(--primary-dark); margin-bottom: 12px; }

.input-group { margin-bottom: 16px; }

.input-group label {
    display: block;
    font-size: 14px;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 6px;
}

.input-group label .required { color: var(--danger); margin-left: 2px; }

.input-group input,
.input-group select,
.input-group textarea {
    width: 100%;
    padding: 10px 14px;
    border: 2px solid var(--border);
    border-radius: 8px;
    font-size: 15px;
    font-family: inherit;
    transition: border-color 0.2s, box-shadow 0.2s;
    background: #fff;
}

.input-group input:focus,
.input-group select:focus,
.input-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(107,45,142,0.1);
}

.input-group input[type=date],
.input-group input[type=month] { background: #F5EEF8; cursor: pointer; }

.input-group input[type=month]::-webkit-calendar-picker-indicator {
    filter: invert(0.4);
    cursor: pointer;
}

.input-group input[type=month]::-moz-calendar-picker-indicator {
    filter: invert(0.4);
    cursor: pointer;
}

.month-picker {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 10px 14px;
    border: 2px solid var(--border);
    border-radius: 8px;
    background: #F5EEF8;
    cursor: pointer;
}

.month-picker select {
    padding: 6px 10px;
    border: 2px solid var(--border);
    border-radius: 6px;
    font-size: 15px;
    font-family: inherit;
    background: #fff;
    cursor: pointer;
    flex: 1;
}

.month-picker select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(107,45,142,0.1);
}

.month-picker span {
    font-size: 15px;
    color: var(--text);
    white-space: nowrap;
}

.input-group textarea { min-height: 80px; resize: vertical; }

.checkbox-group {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 8px;
}

.checkbox-group label {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: normal;
    cursor: pointer;
    padding: 6px 10px;
    border: 1px solid var(--border);
    border-radius: 8px;
    background: #fafbfc;
}

.checkbox-group input { width: auto; accent-color: var(--primary); }

.btn {
    display: inline-block;
    padding: 10px 24px;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    font-size: 15px;
    font-weight: 600;
    transition: all 0.2s;
    text-decoration: none;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--primary-dark));
    color: white;
}

.btn-primary:hover { opacity: 0.9; transform: translateY(-1px); }

.btn-primary:disabled { opacity: 0.5; cursor: not-allowed; transform: none; }

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

.btn-secondary:hover { background: #f5eef8; }

.btn-danger { background: var(--danger); color: white; }

.btn-danger:hover { opacity: 0.9; }

.btn-success { background: var(--success); color: white; }
.btn-warning { background: #f0a020; color: white; }
.btn-warning:hover { opacity: 0.9; }

.btn-sm { padding: 6px 14px; font-size: 13px; }

.btn-block { width: 100%; padding: 12px; font-size: 16px; }

.two-col {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 14px;
}

@media (max-width: 600px) {
    .two-col { grid-template-columns: 1fr; }
    .checkbox-group { grid-template-columns: 1fr; }
}

.flash-messages {
    max-width: 960px;
    margin: 16px auto 0;
    padding: 0 24px;
}

.flash {
    padding: 12px 16px;
    border-radius: 8px;
    margin-bottom: 10px;
}

.flash-success { background: #e8f5e9; color: var(--success); border: 1px solid #a5d6a7; }

.flash-error { background: #ffebee; color: var(--danger); border: 1px solid #ef9a9a; }

.footer {
    text-align: center;
    padding: 30px;
    color: var(--text-muted);
    font-size: 13px;
}

/* Navigation */
.nav {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    flex-wrap: wrap;
    align-items: center;
    justify-content: space-between;
}

.nav-links { display: flex; gap: 10px; flex-wrap: wrap; }

.nav a {
    padding: 8px 16px;
    border-radius: 8px;
    text-decoration: none;
    color: var(--primary);
    background: white;
    border: 1px solid var(--border);
    font-weight: 600;
}

.nav a:hover, .nav a.active { background: #f5eef8; border-color: var(--primary); }

.user-info { color: var(--text-muted); font-size: 14px; }

/* Auth card */
.auth-card { max-width: 420px; margin: 40px auto; }

.auth-card .card-title { text-align: center; margin-bottom: 24px; }

.auth-card .sub-link {
    text-align: center;
    margin-top: 16px;
    color: var(--text-muted);
    font-size: 14px;
}

.auth-card .sub-link a { color: var(--primary); text-decoration: none; }

/* Table */
.table-wrap { overflow-x: auto; }

table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 8px;
    overflow: hidden;
}

th, td {
    padding: 12px 14px;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

th {
    background: var(--primary);
    color: white;
    font-weight: 600;
    white-space: nowrap;
}

tr:hover { background: #faf8fb; }

.actions { display: flex; gap: 6px; flex-wrap: wrap; }

/* Stats grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 20px;
}

.stat-card {
    background: white;
    border-radius: 12px;
    padding: 20px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    text-align: center;
}

.stat-card .number { font-size: 32px; font-weight: 700; color: var(--primary); }

.stat-card .label { color: var(--text-muted); font-size: 14px; margin-top: 6px; }

/* Search bar */
.search-bar {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
    margin-bottom: 16px;
    align-items: flex-end;
}

.search-bar .input-group { margin-bottom: 0; flex: 1; min-width: 160px; }

.search-bar select, .search-bar input { width: 100%; }

/* Upload */
.upload-area {
    border: 2px dashed var(--border);
    border-radius: 10px;
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.2s;
    background: #fafbfc;
}

.upload-area:hover {
    border-color: var(--primary);
    background: #f5eef8;
}

.upload-area .icon { font-size: 40px; margin-bottom: 10px; }

.upload-area p { color: var(--text-muted); font-size: 14px; }

.upload-area .hint { font-size: 12px; color: #999; margin-top: 6px; }

.file-input { display: none; }

.preview-container {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    margin-top: 14px;
}

.preview-item {
    position: relative;
    width: 100px;
    height: 100px;
    border-radius: 8px;
    overflow: hidden;
    border: 2px solid var(--border);
    background: #f0f0f0;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    color: var(--text-muted);
}

.preview-item img { width: 100%; height: 100%; object-fit: cover; }

.preview-item .remove {
    position: absolute;
    top: 2px;
    right: 2px;
    width: 22px;
    height: 22px;
    background: var(--danger);
    color: white;
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 12px;
    line-height: 22px;
}

.empty-state {
    text-align: center;
    padding: 40px 20px;
    color: var(--text-muted);
}

.empty-state .icon { font-size: 48px; margin-bottom: 12px; }

.achievement-card {
    border-left: 4px solid var(--primary);
    padding: 16px 20px;
    margin-bottom: 16px;
    background: white;
    border-radius: 0 8px 8px 0;
    box-shadow: var(--shadow);
}

.achievement-card h4 { color: var(--primary); margin-bottom: 8px; font-size: 16px; }

.achievement-card .meta { color: var(--text-muted); font-size: 13px; margin-bottom: 8px; }

.achievement-card .meta span { margin-right: 14px; }

.achievement-card .desc { font-size: 14px; color: var(--text); margin-bottom: 10px; }

.achievement-card .files { display: flex; gap: 8px; flex-wrap: wrap; }

.achievement-card .files a {
    display: inline-block;
    padding: 4px 10px;
    background: #f5eef8;
    color: var(--primary);
    border-radius: 6px;
    font-size: 13px;
    text-decoration: none;
}

.tabs { display: flex; gap: 8px; margin-bottom: 20px; border-bottom: 2px solid var(--border); }

.tabs a {
    padding: 10px 18px;
    text-decoration: none;
    color: var(--text-muted);
    font-weight: 600;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;
}

.tabs a:hover, .tabs a.active { color: var(--primary); border-bottom-color: var(--primary); }

.auth-links {
    display: flex;
    justify-content: space-between;
    margin-top: 18px;
    font-size: 14px;
}

.auth-links a { color: var(--primary); text-decoration: none; }
.auth-links a:hover { text-decoration: underline; }

.code-row {
    display: flex;
    gap: 10px;
}

.code-row input { flex: 1; }
.code-row button { width: 120px; padding: 10px 12px; font-size: 13px; white-space: nowrap; }

.delete-btn {
    background: var(--danger);
    color: white;
}

.delete-btn:hover { background: #c0392b; }

.reset-password-form {
    display: flex;
    gap: 10px;
    margin-top: 12px;
}

.reset-password-form input { flex: 1; }


.export-panel {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 12px;
}

.export-card {
    background: white;
    border: 1px solid var(--border);
    border-radius: 10px;
    padding: 16px;
}

.export-card h4 { color: var(--primary); margin-bottom: 10px; font-size: 15px; }

.export-card p { font-size: 13px; color: var(--text-muted); margin-bottom: 12px; }

.section-title {
    font-size: 16px;
    color: var(--primary);
    margin: 24px 0 12px;
    padding-bottom: 8px;
    border-bottom: 1px solid var(--border);
}

.teacher-detail dl {
    display: grid;
    grid-template-columns: 120px 1fr;
    gap: 10px 16px;
}

.teacher-detail dt { color: var(--text-muted); font-weight: 600; }

.teacher-detail dd { margin: 0; }

/* Admin achievements table - compact layout */
.admin-achievements-table th,
.admin-achievements-table td {
    padding: 8px 10px;
    font-size: 14px;
}

.admin-achievements-table .achievement-name {
    font-size: 14px;
    line-height: 1.4;
    max-width: 260px;
}

.admin-achievements-table .actions .btn {
    padding: 4px 10px;
    font-size: 12px;
    border-radius: 6px;
}

@media (max-width: 600px) {
    .teacher-detail dl { grid-template-columns: 1fr; }
    .teacher-detail dt { margin-top: 8px; }
    .admin-achievements-table .achievement-name { max-width: 140px; }
}