:root {
    --color-white-soft: #F7FBFF;
    --color-black-soft: #102349;
    --color-primary: #1E3F66;
    --color-primary-soft: rgba(30, 63, 102, 0.6);
    --color-primary-mute: rgba(30, 63, 102, 0.2);
}

body[theme-mode="dark"] {
    --color-background: #102349;
    --color-background-mute: #1B4B77;
    --color-background-soft: #275983;
    --navbar-background-mac: rgba(16, 35, 73, 0.85);
    --navbar-background: #102349;
    --chat-background: #102349;
    --chat-background-user: #1E3F66;
    --chat-background-assistant: #1B4B77;
    --chat-text-user: #F2F7FF;
    --color-text: #F2F7FF;
    --color-hover: #336790;
    --color-active: #3D7BAD;
    --color-border: rgba(242, 247, 255, 0.15);
    --color-border-soft: rgba(242, 247, 255, 0.08);
}

body[theme-mode="light"] {
    --color-background: #F2F7FF;
    --color-background-mute: #B9D7FF;
    --color-background-soft: #D4E5FF;
    --navbar-background: #E6F0FF;
    --chat-background: #F7FBFF;
    --chat-background-user: #D4E5FF;
    --chat-background-assistant: #E6F0FF;
    --color-text: #102349;
    --color-hover: #EBF3FF;
    --color-active: #E0ECFF;
    --color-border: rgba(16, 35, 73, 0.12);
    --color-border-soft: rgba(16, 35, 73, 0.06);
    --color-white: #F7FBFF;
}

* {
    box-sizing: border-box;
}

body {
    margin: 0;
    background: radial-gradient(1200px at 20% 20%, rgba(30, 63, 102, 0.08), transparent), var(--color-background);
    color: var(--color-text);
    font-family: "Inter", "SF Pro Display", "PingFang SC", "Microsoft YaHei", sans-serif;
    line-height: 1.5;
    min-height: 100vh;
    font-size: 15px;
}

.page {
    max-width: 1100px;
    margin: 0 auto;
    padding: 16px;
}

.topbar {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 12px 0;
}

.brand {
    font-weight: 700;
    font-size: 22px;
    letter-spacing: 0.5px;
}

.pill {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    background: var(--color-background-mute);
    color: var(--color-text);
    padding: 6px 12px;
    border-radius: 999px;
    font-size: 13px;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 12px;
}

.card {
    background: var(--color-white-soft);
    border: 1px solid var(--color-border);
    border-radius: 14px;
    padding: 14px;
    box-shadow: 0 8px 20px rgba(16, 35, 73, 0.08);
}

.card h3 {
    margin: 0 0 8px 0;
    font-size: 16px;
}

.btn {
    appearance: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    border: none;
    background: var(--color-primary);
    color: #fff;
    padding: 12px 14px;
    border-radius: 10px;
    font-weight: 600;
    font-size: 15px;
    width: 100%;
    cursor: pointer;
    transition: transform 0.12s ease, box-shadow 0.12s ease;
    box-shadow: 0 8px 20px rgba(30, 63, 102, 0.25);
    text-decoration: none;
}

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

.btn.secondary {
    background: var(--color-background-soft);
    color: var(--color-text);
    box-shadow: none;
}

.btn.ghost {
    background: transparent;
    color: var(--color-primary);
    border: 1px dashed var(--color-primary-mute);
    box-shadow: none;
}

.btn.submit-small {
    width: auto;
    padding: 10px 14px;
}
.btn.submit-accent {
    width: 100%;
    background: linear-gradient(135deg, #1E3F66, #2a5a9a);
    color: #fff;
    box-shadow: 0 10px 20px rgba(30, 63, 102, 0.35);
}

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

.input {
    width: 100%;
    padding: 12px;
    border-radius: 10px;
    border: 1px solid var(--color-border);
    background: #fff;
    color: var(--color-text);
    font-size: 15px;
}

.tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 10px;
    background: var(--color-background-soft);
    border-radius: 999px;
    font-size: 13px;
}

.question-card {
    padding: 12px;
    border-radius: 12px;
    background: #fff;
    border: 1px solid var(--color-border);
}

.options {
    display: flex;
    flex-direction: column;
    gap: 8px;
    margin: 8px 0 0 0;
}

.option {
    border: 1px solid var(--color-border);
    border-radius: 10px;
    padding: 10px 12px;
    background: var(--color-white-soft);
    display: flex;
    gap: 10px;
    align-items: center;
}

.option input {
    transform: scale(1.1);
}

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

.chip {
    padding: 6px 10px;
    background: var(--color-background-soft);
    border-radius: 10px;
    font-size: 12px;
    cursor: pointer;
}

.chip.active {
    background: var(--color-primary);
    color: #fff;
}

.floating-action {
    position: fixed;
    right: 16px;
    bottom: 16px;
    z-index: 10;
}

.divider {
    height: 1px;
    width: 100%;
    background: var(--color-border);
    margin: 12px 0;
}

.leaderboard {
    display: grid;
    gap: 10px;
}

.lb-grid {
    display: grid;
    gap: 10px;
    grid-template-columns: repeat(auto-fit, minmax(260px, 1fr));
}

.lb-row {
    display: grid;
    grid-template-columns: 52px 1fr 70px 90px;
    align-items: center;
    gap: 10px;
    padding: 10px;
    border-radius: 10px;
    background: #fff;
    border: 1px solid var(--color-border);
}

.lb-row.rank-1 {
    border: 1px solid #f2c94c;
}
.lb-row.rank-2 {
    border: 1px solid #9b9b9b;
}
.lb-row.rank-3 {
    border: 1px solid #c47b46;
}

.lb-card {
    display: grid;
    grid-template-columns: 1fr;
    gap: 8px;
    padding: 12px;
    border-radius: 14px;
    background: linear-gradient(145deg, #fff, var(--color-white-soft));
    border: 1px solid var(--color-border);
    box-shadow: 0 8px 18px rgba(16, 35, 73, 0.12);
}

.lb-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 6px;
    font-size: 12px;
    color: var(--color-text);
}

.lb-score {
    font-weight: 700;
    color: var(--color-primary);
}

.badge {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary);
    color: #fff;
    min-width: 32px;
    padding: 6px 10px;
    border-radius: 10px;
    font-weight: 700;
}
.lb-card.rank-1 .badge {
    background: #f2c94c;
    color: #102349;
}
.lb-card.rank-2 .badge {
    background: #cbd5e0;
    color: #102349;
}
.lb-card.rank-3 .badge {
    background: #c47b46;
}

.modal-backdrop {
    position: fixed;
    inset: 0;
    background: rgba(16, 35, 73, 0.2);
    backdrop-filter: blur(2px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 20;
    padding: 16px;
}

.modal {
    background: #fff;
    border-radius: 14px;
    padding: 14px;
    width: min(720px, 100%);
    border: 1px solid var(--color-border);
    box-shadow: 0 10px 30px rgba(16, 35, 73, 0.2);
}

.progress {
    flex: 1;
    background: var(--color-background-soft);
    border-radius: 999px;
    overflow: hidden;
    height: 12px;
    margin-left: 10px;
}

.progress-bar {
    height: 100%;
    background: var(--color-primary);
    width: 0;
    transition: width 0.2s ease;
}

.jump-grid {
    grid-template-columns: repeat(auto-fit, minmax(64px, 1fr));
}

.two-col-mobile {
    grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
    gap: 10px;
}

.action-card {
    display: grid;
    gap: 10px;
    grid-template-columns: repeat(auto-fit, minmax(160px, 1fr));
    align-items: center;
}

.flex {
    display: flex;
    gap: 8px;
    align-items: center;
}

.flex.between {
    justify-content: space-between;
}

.timer {
    font-weight: 700;
    color: var(--color-primary);
}

.hint {
    background: var(--color-background-soft);
    border-radius: 8px;
    padding: 8px 10px;
    font-size: 13px;
}

.panel {
    background: #fff;
    border: 1px dashed var(--color-border);
    padding: 12px;
    border-radius: 12px;
}

.success {
    color: #1f9d55;
}

.danger {
    color: #d64545;
}
.warning {
    color: #b7791f;
}

.small {
    font-size: 12px;
    opacity: 0.8;
}

.emphasis {
    font-weight: 700;
}

.top-actions {
    gap: 10px;
}

.nav-row {
    align-items: center;
}

.card-error {
    border-color: #d64545;
    background: #fff6f6;
}

.card-correct {
    border-color: #0e9f6e;
    background: #f1fcf5;
}

.page-wide {
    max-width: 1280px;
}

.lb-user {
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.user-name {
    font-weight: 700;
    font-size: 18px;
    color: var(--color-black-soft);
}

.lb-dept .chip {
    margin-left: 4px;
}

.chip.dept {
    border: 1px solid transparent;
    font-weight: 600;
}

.tag.accent {
    background: linear-gradient(135deg, #1E3F66, #2a5a9a);
    color: #fff;
}

.tag.mild {
    background: var(--color-background-mute);
    color: var(--color-text);
}

.lb-card.rank-1 {
    border: 1px solid #f2c94c;
    box-shadow: 0 10px 24px rgba(242, 201, 76, 0.35);
}
.lb-card.rank-2 {
    border: 1px solid #9b9b9b;
    box-shadow: 0 10px 24px rgba(155, 155, 155, 0.25);
}
.lb-card.rank-3 {
    border: 1px solid #c47b46;
    box-shadow: 0 10px 24px rgba(196, 123, 70, 0.25);
}

.list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.list-row {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 10px;
    padding: 10px;
    border: 1px solid var(--color-border);
    border-radius: 10px;
    background: #fff;
}

.field-block {
    border: 1px solid var(--color-border);
    border-radius: 10px;
    padding: 10px;
    background: #fff;
}

@media (max-width: 680px) {
    .page {
        padding: 12px;
    }
    .grid {
        grid-template-columns: 1fr;
    }
    .lb-row {
        grid-template-columns: 36px 1fr 60px 68px;
        font-size: 13px;
    }
}