/* Local font: drop WanYuanTi.woff2 into fonts/ to activate */
@font-face {
    font-family: 'WanYuanTi';
    src: url('fonts/WanYuanTi.woff2') format('woff2'),
         url('fonts/WanYuanTi.ttf') format('truetype');
    font-weight: normal;
    font-style: normal;
    font-display: swap;
}

:root {
    --primary: #FF6B9D;
    --primary-light: #FFB5CC;
    --primary-dark: #E8527F;
    --secondary: #B4A0E5;
    --secondary-light: #D4C7F0;
    --accent: #67E8F9;
    --mint: #7DCEA0;
    --warm: #FFD93D;
    --danger: #FF6B6B;
    --orange: #FF9A3C;
    --orange-light: #FFB86C;
    --orange-dark: #F08C28;
    --bg: #FFF5F7;
    --card: rgba(255, 255, 255, 0.92);
    --card-solid: #ffffff;
    --card-hover: rgba(255, 255, 255, 0.96);
    --text: #4A4A6A;
    --text-light: #9898B8;
    --border: #F0E0E8;
    --shadow: 0 4px 24px rgba(255, 107, 157, 0.12);
    --shadow-hover: 0 8px 32px rgba(255, 107, 157, 0.2);
    --radius: 18px;
    --radius-sm: 12px;
    --radius-xs: 8px;
    --font-cute: 'WanYuanTi', 'ZCOOL KuaiLe', cursive;
    --font-body: 'Noto Sans SC', -apple-system, BlinkMacSystemFont, sans-serif;
    --sidebar-w: 280px;
    --header-h: 72px;
}

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

html { scroll-behavior: smooth; }

body {
    font-family: var(--font-body);
    color: var(--text);
    background: var(--bg);
    min-height: 100vh;
    overflow-x: hidden;
}

.hidden { display: none !important; }

#bg-layer {
    position: fixed; inset: 0;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    z-index: -2;
    transition: opacity 0.6s ease;
}
#bg-layer.has-bg::after {
    content: '';
    position: absolute; inset: 0;
    background: rgba(255, 250, 248, 0.3);
}

#particles {
    position: fixed; inset: 0;
    pointer-events: none;
    z-index: -1;
    overflow: hidden;
}
.particle {
    position: absolute;
    font-size: 16px;
    opacity: 0;
    animation: floatUp 6s ease-in infinite;
}
@keyframes floatUp {
    0% { opacity: 0; transform: translateY(100vh) rotate(0deg); }
    10% { opacity: 0.7; }
    90% { opacity: 0.7; }
    100% { opacity: 0; transform: translateY(-10vh) rotate(360deg); }
}

/* ===== HEADER ===== */
#header {
    position: sticky; top: 0; z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 28px;
    height: var(--header-h);
    background: linear-gradient(135deg, rgba(255,154,60,0.95), rgba(255,184,108,0.95));
    backdrop-filter: blur(12px);
    box-shadow: 0 2px 20px rgba(255,154,60,0.3);
}
.site-title {
    font-family: var(--font-cute);
    font-size: 26px;
    color: #fff;
    text-shadow: 0 2px 8px rgba(0,0,0,0.12);
    letter-spacing: 1px;
}
.subtitle {
    font-size: 12px;
    color: rgba(255,255,255,0.85);
    margin-top: 2px;
}
.header-right { display: flex; gap: 8px; }
.header-btn {
    display: inline-flex; align-items: center; gap: 4px;
    padding: 8px 14px;
    background: rgba(255,255,255,0.2);
    border: 1px solid rgba(255,255,255,0.3);
    border-radius: var(--radius-xs);
    color: #fff;
    font-size: 13px;
    font-family: var(--font-body);
    cursor: pointer;
    text-decoration: none;
    transition: all 0.25s;
    white-space: nowrap;
}
.header-btn:hover { background: rgba(255,255,255,0.35); transform: translateY(-1px); }

/* ===== LAYOUT ===== */
.main-layout {
    display: flex;
    min-height: calc(100vh - var(--header-h));
}

/* ===== SIDEBAR ===== */
#sidebar {
    width: var(--sidebar-w);
    min-width: var(--sidebar-w);
    padding: 20px 16px;
    background: var(--card);
    backdrop-filter: blur(10px);
    border-right: 1px solid var(--border);
    overflow-y: auto;
    height: calc(100vh - var(--header-h));
    position: sticky;
    top: var(--header-h);
}
.sidebar-section {
    margin-bottom: 24px;
}
.sidebar-section h3 {
    font-family: var(--font-cute);
    font-size: 16px;
    color: var(--primary);
    margin-bottom: 12px;
    padding-bottom: 6px;
    border-bottom: 2px dashed var(--primary-light);
}

/* Progress Ring */
.progress-ring-container {
    display: flex; justify-content: center;
    margin-bottom: 12px;
}
.progress-ring { width: 110px; height: 110px; }
.progress-ring-bg {
    fill: none; stroke: var(--border); stroke-width: 8;
}
.progress-ring-fill {
    fill: none; stroke: var(--primary); stroke-width: 8;
    stroke-linecap: round;
    stroke-dasharray: 326.73;
    stroke-dashoffset: 326.73;
    transform: rotate(-90deg);
    transform-origin: center;
    transition: stroke-dashoffset 0.8s ease;
}
.progress-ring-text {
    font-family: var(--font-cute);
    font-size: 22px; fill: var(--primary);
    text-anchor: middle;
}
.progress-ring-sub {
    font-size: 11px; fill: var(--text-light);
    text-anchor: middle;
}

.progress-stats {
    display: flex; justify-content: center; gap: 10px; flex-wrap: wrap;
}
.stat {
    font-size: 12px; padding: 3px 8px;
    background: var(--bg); border-radius: 20px;
    white-space: nowrap;
}

/* Day Navigation */
.day-nav {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 6px;
}
.day-btn {
    position: relative;
    padding: 10px 8px;
    border: 2px solid var(--border);
    border-radius: var(--radius-xs);
    background: #fff;
    cursor: pointer;
    transition: all 0.25s;
    text-align: center;
    font-family: var(--font-body);
    font-size: 12px;
    color: var(--text);
}
.day-btn:hover { border-color: var(--primary-light); transform: translateY(-1px); }
.day-btn.active {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: #fff; border-color: transparent;
    box-shadow: 0 3px 12px rgba(255,107,157,0.3);
}
.day-btn .day-num {
    font-family: var(--font-cute);
    font-size: 15px;
    display: block;
}
.day-btn .day-status {
    position: absolute; top: 3px; right: 5px;
    font-size: 10px;
}

/* Music Section */
.music-section iframe {
    border-radius: var(--radius-xs);
    width: 100%;
}
.empty-hint {
    font-size: 13px; color: var(--text-light);
    text-align: center; padding: 16px 0;
}

/* ===== MAIN CONTENT ===== */
#main-content {
    flex: 1;
    padding: 24px 32px;
    max-width: 1150px;
}

/* Tabs */
.tabs {
    display: flex; gap: 4px;
    margin-bottom: 20px;
    background: var(--card);
    border-radius: var(--radius);
    padding: 4px;
    box-shadow: var(--shadow);
}
.tab {
    flex: 1;
    padding: 12px 16px;
    border: none;
    border-radius: calc(var(--radius) - 4px);
    background: transparent;
    font-family: var(--font-cute);
    font-size: 15px;
    color: var(--text-light);
    cursor: pointer;
    transition: all 0.3s;
}
.tab:hover { color: var(--text); background: rgba(255,107,157,0.08); }
.tab.active {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: #fff;
    box-shadow: 0 3px 12px rgba(255,107,157,0.3);
}

.tab-content { display: none; animation: fadeIn 0.3s ease; }
.tab-content.active { display: block; }
@keyframes fadeIn { from { opacity: 0; transform: translateY(8px); } to { opacity: 1; transform: translateY(0); } }

/* Bailian training set */
.bailian-board {
    background: var(--card);
    border-radius: var(--radius);
    padding: 18px;
    box-shadow: var(--shadow);
    border-left: 5px solid var(--orange);
}

.bailian-embed-card {
    background: var(--card);
    border-radius: var(--radius);
    padding: 18px;
    box-shadow: var(--shadow);
    border-left: 5px solid var(--orange);
}

.bailian-embed-head {
    display: flex;
    align-items: flex-start;
    justify-content: space-between;
    gap: 14px;
    margin-bottom: 14px;
}

.bailian-embed-head h2 {
    font-family: var(--font-cute);
    color: var(--orange-dark);
    margin-bottom: 6px;
}

.bailian-embed-head p {
    color: var(--text-light);
    font-size: 14px;
    line-height: 1.7;
}

.bailian-header-actions {
    display: flex;
    flex-wrap: wrap;
    justify-content: flex-end;
    gap: 8px;
}

.bailian-iframe {
    width: 100%;
    min-height: 760px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: #fffdf8;
}

.bailian-stats {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 16px;
}

.bailian-stats span {
    padding: 5px 12px;
    border-radius: 999px;
    background: var(--bg);
    color: var(--text);
    font-size: 13px;
}

.bailian-catalog {
    margin-bottom: 16px;
    padding: 12px;
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.68);
    border: 1px dashed var(--border);
}

.bailian-catalog-title {
    margin-bottom: 8px;
    font-family: var(--font-cute);
    color: var(--orange-dark);
}

.bailian-catalog-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 8px;
}

.bailian-catalog-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 8px;
    padding: 8px 10px;
    border: 1px solid var(--border);
    border-radius: var(--radius-xs);
    background: #fff;
    color: var(--text);
    cursor: pointer;
    text-align: left;
    transition: all 0.2s ease;
}

.bailian-catalog-item:hover {
    border-color: var(--orange-light);
    transform: translateY(-1px);
}

.bailian-catalog-item small {
    color: var(--text-light);
    white-space: nowrap;
}

.bailian-section {
    margin-top: 16px;
    padding: 16px;
    border: 1px solid var(--border);
    border-radius: var(--radius-sm);
    background: rgba(255,255,255,0.72);
}

.bailian-section-head {
    margin-bottom: 12px;
}

.bailian-section-head h3 {
    font-family: var(--font-cute);
    color: var(--orange-dark);
    margin-bottom: 4px;
}

.bailian-section-head p {
    color: var(--text-light);
    font-size: 13px;
}

.bailian-problem-list {
    display: grid;
    gap: 10px;
}

.bailian-problem {
    margin-bottom: 0;
    background: rgba(255,255,255,0.9);
}

.bailian-problem .problem-top {
    align-items: flex-start;
}

.bailian-wrong-entry {
    border-left-color: var(--orange);
}

.wrong-source-summary {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 12px;
}

.wrong-source-summary span {
    padding: 5px 12px;
    border-radius: 999px;
    background: var(--bg);
    color: var(--text-light);
    font-size: 12px;
}

/* Day Header */
.day-header {
    background: var(--card);
    border-radius: var(--radius);
    padding: 24px;
    margin-bottom: 20px;
    box-shadow: var(--shadow);
    border-left: 5px solid var(--primary);
}
.day-header h2 {
    font-family: var(--font-cute);
    font-size: 24px;
    color: var(--primary-dark);
    margin-bottom: 6px;
}
.day-header .day-goal {
    font-size: 14px;
    color: var(--text-light);
}
.day-header .chapter-tag {
    display: inline-block;
    padding: 2px 10px;
    background: var(--secondary-light);
    border-radius: 20px;
    font-size: 12px;
    color: var(--secondary);
    margin-top: 8px;
    font-weight: 500;
}

/* Problem Card */
.problem-card {
    background: var(--card);
    border-radius: var(--radius);
    padding: 20px;
    margin-bottom: 14px;
    box-shadow: var(--shadow);
    transition: all 0.3s;
    border: 2px solid transparent;
}
.problem-card:hover { box-shadow: var(--shadow-hover); border-color: var(--primary-light); }
.problem-card.status-completed { border-left: 5px solid var(--mint); }
.problem-card.status-wrong { border-left: 5px solid var(--danger); }
.problem-card.status-in_progress { border-left: 5px solid var(--warm); }

.problem-top {
    display: flex; align-items: center; justify-content: space-between;
    margin-bottom: 10px; flex-wrap: wrap; gap: 8px;
}
.problem-info { display: flex; align-items: center; gap: 10px; flex-wrap: wrap; }
.problem-id {
    font-family: var(--font-cute);
    font-size: 18px;
    color: var(--primary);
}
.problem-id a {
    color: inherit; text-decoration: none;
    transition: color 0.2s;
}
.problem-id a:hover { color: var(--primary-dark); text-decoration: underline; }
.problem-name {
    font-size: 15px; font-weight: 500;
}
.badge {
    display: inline-block; padding: 2px 8px;
    border-radius: 20px; font-size: 11px;
    font-weight: 500;
}
.badge-review { background: #FFF3CD; color: #856404; }
.badge-optional { background: #E0F0FF; color: #0066CC; }

.problem-desc {
    font-size: 13px; color: var(--text-light);
    margin-bottom: 12px;
    padding: 8px 12px;
    background: var(--bg);
    border-radius: var(--radius-xs);
}

/* Status Selector */
.status-selector { display: flex; gap: 4px; }
.status-btn {
    padding: 5px 10px;
    border: 2px solid var(--border);
    border-radius: 20px;
    background: #fff;
    font-size: 12px;
    cursor: pointer;
    transition: all 0.2s;
    font-family: var(--font-body);
}
.status-btn:hover { border-color: var(--primary-light); }
.status-btn.active-not_started { border-color: var(--text-light); background: #f0f0f5; }
.status-btn.active-in_progress { border-color: var(--warm); background: #FFF8E1; }
.status-btn.active-completed { border-color: var(--mint); background: #E8F8F0; }
.status-btn.active-wrong { border-color: var(--danger); background: #FFF0F0; }

/* Expandable Sections */
.expand-toggle {
    display: inline-flex; align-items: center; gap: 4px;
    padding: 5px 12px;
    background: none; border: 1px dashed var(--border);
    border-radius: 20px;
    font-size: 12px; color: var(--text-light);
    cursor: pointer;
    transition: all 0.2s;
    font-family: var(--font-body);
    margin-right: 6px;
    margin-top: 4px;
}
.expand-toggle:hover { border-color: var(--primary); color: var(--primary); }
.expand-toggle.open { background: var(--bg); border-style: solid; color: var(--text); }

.expandable {
    max-height: 0; overflow: hidden;
    transition: max-height 0.4s ease, padding 0.3s ease;
}
.expandable.open {
    max-height: none;
    padding-top: 12px;
}

.note-area, .wrong-area {
    margin-top: 8px;
}
.note-area textarea, .wrong-area textarea {
    width: 100%;
    min-height: 80px;
    padding: 12px;
    border: 2px solid var(--border);
    border-radius: var(--radius-xs);
    font-family: var(--font-body);
    font-size: 13px;
    resize: vertical;
    transition: border-color 0.2s;
    background: #fff;
    color: var(--text);
}
.note-area textarea:focus, .wrong-area textarea:focus {
    outline: none;
    border-color: var(--primary-light);
    box-shadow: 0 0 0 3px rgba(255,107,157,0.1);
}
.wrong-area label {
    display: block;
    font-size: 12px;
    font-weight: 500;
    color: var(--text-light);
    margin-bottom: 4px;
    margin-top: 10px;
}
.wrong-area label:first-child { margin-top: 0; }

/* Reflections */
.reflections {
    background: var(--card);
    border-radius: var(--radius);
    padding: 20px;
    margin-top: 20px;
    box-shadow: var(--shadow);
}
.reflections h3 {
    font-family: var(--font-cute);
    font-size: 17px; color: var(--secondary);
    margin-bottom: 12px;
}
.reflection-item {
    display: flex; align-items: flex-start; gap: 8px;
    padding: 8px 0;
    font-size: 14px;
    border-bottom: 1px dashed var(--border);
}
.reflection-item:last-child { border: none; }
.reflection-item .icon { font-size: 16px; flex-shrink: 0; margin-top: 1px; }

/* ===== WRONG NOTEBOOK TAB ===== */
.wrong-notebook-empty {
    text-align: center; padding: 60px 20px;
    color: var(--text-light);
}
.wrong-notebook-empty .big-icon { font-size: 48px; margin-bottom: 12px; }
.wrong-entry {
    background: var(--card);
    border-radius: var(--radius);
    padding: 20px; margin-bottom: 14px;
    box-shadow: var(--shadow);
    border-left: 5px solid var(--danger);
}
.wrong-entry-header {
    display: flex; align-items: center; justify-content: space-between;
    margin-bottom: 10px;
}
.card-header-actions, .think-entry-head, .journal-entry-head {
    display: flex; align-items: center; justify-content: space-between;
    gap: 8px;
}
.card-fold-btn {
    flex-shrink: 0;
    padding: 4px 10px;
    border: 1px dashed var(--border);
    border-radius: 16px;
    background: #fff;
    color: var(--text-light);
    font-family: var(--font-body);
    font-size: 12px;
    cursor: pointer;
    transition: all .2s;
}
.card-fold-btn:hover { border-color: var(--primary); color: var(--primary); background: var(--bg); }
.collapsible-card.collapsed .collapsible-card-body { display: none; }
.collapsible-card.collapsed { padding-bottom: 14px; }
.wrong-entry-id {
    font-family: var(--font-cute);
    font-size: 18px; color: var(--danger);
}
.wrong-entry-day {
    font-size: 12px; color: var(--text-light);
    background: var(--bg); padding: 3px 10px;
    border-radius: 20px;
}
.wrong-detail { margin-top: 8px; }
.wrong-detail-label {
    font-size: 12px; color: var(--text-light);
    font-weight: 500; margin-bottom: 4px;
}
.wrong-detail-content {
    font-size: 14px; padding: 8px 12px;
    background: var(--bg);
    border-radius: var(--radius-xs);
    margin-bottom: 8px;
    white-space: pre-wrap;
    line-height: 1.6;
}

/* ===== JOURNAL TAB ===== */
.journal-day {
    background: var(--card);
    border-radius: var(--radius);
    padding: 20px; margin-bottom: 14px;
    box-shadow: var(--shadow);
}
.journal-day-title {
    font-family: var(--font-cute);
    font-size: 18px; color: var(--secondary);
    margin-bottom: 12px;
    display: flex; align-items: center; gap: 8px;
}
.journal-entries { margin-bottom: 12px; }
.journal-entry {
    padding: 10px 14px;
    background: var(--bg);
    border-radius: var(--radius-xs);
    margin-bottom: 8px;
    position: relative;
}
.journal-entry-date {
    font-size: 11px; color: var(--text-light);
    margin-bottom: 4px;
}
.journal-entry-head { padding-right: 24px; margin-bottom: 4px; }
.journal-entry-content {
    font-size: 14px; line-height: 1.6;
}
.journal-entry-content img { max-width: 100%; border-radius: var(--radius-xs); margin: 6px 0; }
.journal-entry-content p { margin: 4px 0; white-space: pre-wrap; }
.journal-entry-content code { background: #f0f0f5; padding: 1px 5px; border-radius: 4px; font-size: 13px; }
.journal-entry-content pre { background: #f0f0f5; padding: 10px; border-radius: var(--radius-xs); overflow-x: auto; }
.journal-entry-content pre code { background: none; padding: 0; }
.journal-input-wrap { display: flex; flex-direction: column; gap: 6px; }
.journal-entry-delete {
    position: absolute; top: 8px; right: 8px;
    background: none; border: none;
    font-size: 14px; cursor: pointer;
    color: var(--text-light);
    opacity: 0; transition: opacity 0.2s;
}
.journal-entry:hover .journal-entry-delete { opacity: 1; }

.journal-input-row {
    display: flex; gap: 8px;
}
.journal-input-row textarea {
    flex: 1; padding: 10px 14px;
    border: 2px solid var(--border);
    border-radius: var(--radius-xs);
    font-family: var(--font-body);
    font-size: 13px; resize: vertical;
    min-height: 60px;
    transition: border-color 0.2s;
}
.journal-input-row textarea:focus {
    outline: none; border-color: var(--primary-light);
}
.journal-input-row .btn {
    align-self: flex-end;
}

/* ===== MODAL ===== */
.modal {
    display: none;
    position: fixed; inset: 0;
    z-index: 1000;
    align-items: center; justify-content: center;
}
.modal.open { display: flex; }
.modal-overlay {
    position: absolute; inset: 0;
    background: rgba(74,74,106,0.4);
    backdrop-filter: blur(4px);
}
.modal-content {
    position: relative;
    background: var(--card-solid);
    border-radius: var(--radius);
    width: 90%; max-width: 560px;
    max-height: 85vh;
    overflow-y: auto;
    box-shadow: 0 20px 60px rgba(0,0,0,0.15);
    animation: modalIn 0.3s ease;
}
@keyframes modalIn { from { opacity:0; transform: scale(0.95) translateY(10px); } }

.modal-header {
    display: flex; align-items: center; justify-content: space-between;
    padding: 20px 24px 12px;
    border-bottom: 1px solid var(--border);
}
.modal-header h2 {
    font-family: var(--font-cute);
    font-size: 20px; color: var(--primary);
}
.modal-close {
    width: 32px; height: 32px;
    border: none; border-radius: 50%;
    background: var(--bg);
    font-size: 20px; color: var(--text-light);
    cursor: pointer;
    transition: all 0.2s;
    display: flex; align-items: center; justify-content: center;
}
.modal-close:hover { background: var(--primary-light); color: #fff; }
.modal-body { padding: 20px 24px 24px; }

/* Settings */
.settings-group {
    margin-bottom: 24px;
    padding-bottom: 20px;
    border-bottom: 1px dashed var(--border);
}
.settings-group:last-child { border: none; margin-bottom: 0; }
.settings-group h3 {
    font-family: var(--font-cute);
    font-size: 16px; color: var(--secondary);
    margin-bottom: 12px;
}
.settings-group label {
    display: block; font-size: 12px;
    color: var(--text-light); margin-bottom: 4px; margin-top: 10px;
}
.settings-group label:first-of-type { margin-top: 0; }
.settings-group input[type="text"] {
    width: 100%; padding: 10px 14px;
    border: 2px solid var(--border);
    border-radius: var(--radius-xs);
    font-size: 14px;
    font-family: var(--font-body);
    transition: border-color 0.2s;
    color: var(--text);
}
.settings-group input[type="text"]:focus {
    outline: none; border-color: var(--primary-light);
}

.bg-upload-area { margin-bottom: 12px; }
.upload-hint { font-size: 12px; color: var(--text-light); margin-left: 8px; }

.bg-preview-list {
    display: flex; gap: 8px; flex-wrap: wrap;
    margin-bottom: 12px;
}
.bg-preview-item {
    position: relative; width: 80px; height: 60px;
    border-radius: var(--radius-xs);
    overflow: hidden; cursor: pointer;
    border: 3px solid transparent;
    transition: all 0.2s;
}
.bg-preview-item.active { border-color: var(--primary); }
.bg-preview-item img {
    width: 100%; height: 100%; object-fit: cover;
}
.bg-preview-delete {
    position: absolute; top: 2px; right: 2px;
    width: 18px; height: 18px;
    background: rgba(255,107,107,0.9);
    border: none; border-radius: 50%;
    color: #fff; font-size: 11px;
    cursor: pointer; display: flex;
    align-items: center; justify-content: center;
    opacity: 0; transition: opacity 0.2s;
}
.bg-preview-item:hover .bg-preview-delete { opacity: 1; }

.music-add-row { display: flex; gap: 8px; margin-bottom: 12px; }
.music-add-row input { flex: 1; }
.music-manage-list { display: flex; flex-direction: column; gap: 6px; }
.music-manage-item {
    display: flex; align-items: center; justify-content: space-between;
    padding: 8px 12px;
    background: var(--bg);
    border-radius: var(--radius-xs);
    font-size: 13px;
}
.music-manage-item button {
    background: none; border: none;
    color: var(--danger); cursor: pointer;
    font-size: 14px;
}

.data-actions { display: flex; gap: 8px; }

/* Buttons */
.btn {
    padding: 9px 18px;
    border: none; border-radius: var(--radius-xs);
    font-family: var(--font-body);
    font-size: 13px; font-weight: 500;
    cursor: pointer; transition: all 0.25s;
    display: inline-flex; align-items: center; gap: 4px;
    white-space: nowrap;
}
.btn-primary {
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: #fff;
}
.btn-primary:hover { box-shadow: 0 4px 16px rgba(255,107,157,0.35); transform: translateY(-1px); }
.btn-secondary {
    background: var(--bg); color: var(--text);
    border: 1px solid var(--border);
}
.btn-secondary:hover { border-color: var(--primary-light); }
.btn-accent {
    background: var(--accent); color: #1a3a4a;
}
.btn-accent:hover { box-shadow: 0 4px 12px rgba(103,232,249,0.35); }
.btn-danger {
    background: #FFF0F0; color: var(--danger);
    border: 1px solid #FFD0D0;
}
.btn-sm { padding: 5px 12px; font-size: 12px; }

/* ===== ADD PROBLEM FORM ===== */
.add-problem-section {
    background: var(--card);
    border-radius: var(--radius);
    padding: 16px 20px;
    margin-bottom: 14px;
    box-shadow: var(--shadow);
    border: 2px dashed var(--orange-light);
}
.add-problem-section h4 {
    font-family: var(--font-cute);
    font-size: 14px;
    color: var(--orange);
    margin-bottom: 10px;
}
.add-problem-row {
    display: flex; gap: 8px; flex-wrap: wrap;
}
.add-problem-row input {
    padding: 8px 12px;
    border: 2px solid var(--border);
    border-radius: var(--radius-xs);
    font-family: var(--font-body);
    font-size: 13px;
    transition: border-color 0.2s;
    color: var(--text);
}
.add-problem-row input:focus {
    outline: none;
    border-color: var(--orange-light);
}
.add-problem-row input:first-child { width: 120px; }
.add-problem-row input:nth-child(2) { flex: 1; min-width: 140px; }
.btn-orange {
    background: linear-gradient(135deg, var(--orange), var(--orange-light));
    color: #fff;
}
.btn-orange:hover { box-shadow: 0 4px 16px rgba(255,154,60,0.35); transform: translateY(-1px); }

.custom-problem-delete {
    background: none; border: none;
    color: var(--text-light); cursor: pointer;
    font-size: 16px; padding: 2px 6px;
    border-radius: 4px;
    transition: all 0.2s;
    margin-left: 8px;
}
.custom-problem-delete:hover { color: var(--danger); background: #FFF0F0; }
.badge-custom { background: #FFF0E0; color: var(--orange-dark); }

/* ===== NOTE TOOLBAR & MARKDOWN ===== */
.note-toolbar {
    display: flex; gap: 6px; margin-bottom: 8px;
}
.note-tool-btn {
    display: inline-flex; align-items: center; gap: 3px;
    padding: 4px 10px;
    background: var(--bg); border: 1px solid var(--border);
    border-radius: 16px; font-size: 12px;
    color: var(--text-light); cursor: pointer;
    transition: all 0.2s; font-family: var(--font-body);
}
.note-tool-btn:hover { border-color: var(--primary); color: var(--primary); }
.note-tool-btn input[type="file"] { display: none; }

.note-preview {
    padding: 12px; background: #fff;
    border: 2px solid var(--border);
    border-radius: var(--radius-xs);
    font-size: 14px; line-height: 1.7; min-height: 80px;
}
.note-preview img { max-width: 100%; border-radius: var(--radius-xs); margin: 8px 0; }
.note-preview code {
    background: #f0f0f5; padding: 1px 5px; border-radius: 4px; font-size: 13px;
}
.note-preview pre {
    background: #f0f0f5; padding: 12px; border-radius: var(--radius-xs);
    overflow-x: auto; margin: 8px 0;
}
.note-preview pre code { background: none; padding: 0; }
.note-preview h1, .note-preview h2, .note-preview h3 {
    font-family: var(--font-cute); color: var(--primary-dark); margin: 12px 0 6px;
}
.note-preview blockquote {
    border-left: 3px solid var(--primary-light); padding-left: 12px;
    color: var(--text-light); margin: 8px 0;
}
.note-preview ul, .note-preview ol { padding-left: 20px; margin: 8px 0; }
.note-preview p { margin: 6px 0; }

/* ===== STAR TOGGLE ===== */
.star-toggle {
    display: inline-flex; align-items: center; gap: 3px;
    padding: 5px 12px; background: none;
    border: 1px dashed var(--border); border-radius: 20px;
    font-size: 12px; color: var(--text-light);
    cursor: pointer; transition: all 0.2s;
    font-family: var(--font-body);
    margin-right: 6px; margin-top: 4px;
}
.star-toggle:hover { border-color: var(--warm); color: var(--warm); }
.star-toggle.starred {
    background: #FFF8E1; border: 1px solid var(--warm);
    color: #B8860B; border-style: solid;
}

/* ===== STAR TAB ===== */
.star-empty {
    text-align: center; padding: 60px 20px; color: var(--text-light);
}
.star-empty .big-icon { font-size: 48px; margin-bottom: 12px; }
.star-entry {
    background: var(--card); border-radius: var(--radius);
    padding: 20px; margin-bottom: 14px;
    box-shadow: var(--shadow); border-left: 5px solid var(--warm);
}
.star-entry-header {
    display: flex; align-items: center; justify-content: space-between;
    margin-bottom: 12px; flex-wrap: wrap; gap: 8px;
}
.star-entry-id { font-family: var(--font-cute); font-size: 18px; color: var(--orange); }
.star-entry-id a { color: inherit; text-decoration: none; }
.star-entry-id a:hover { text-decoration: underline; }
.star-entry-day {
    font-size: 12px; color: var(--text-light);
    background: var(--bg); padding: 3px 10px; border-radius: 20px;
}
.star-note-section { margin-top: 12px; }
.star-note-section h4 {
    font-family: var(--font-cute); font-size: 14px; color: #B8860B; margin-bottom: 8px;
}
.star-note-textarea {
    width: 100%; min-height: 100px; padding: 12px;
    border: 2px solid var(--border); border-radius: var(--radius-xs);
    font-family: var(--font-body); font-size: 13px;
    resize: vertical; background: #fff; color: var(--text);
    transition: border-color 0.2s;
}
.star-note-textarea:focus {
    outline: none; border-color: var(--warm);
    box-shadow: 0 0 0 3px rgba(255,217,61,0.1);
}
.star-regular-note {
    margin-top: 16px; padding-top: 12px; border-top: 1px dashed var(--border);
}
.star-regular-note h4 {
    font-family: var(--font-cute); font-size: 14px;
    color: var(--secondary); margin-bottom: 8px;
}

/* ===== NOTE COLLAPSED PREVIEW ===== */
.note-collapsed-preview {
    padding: 10px 14px;
    background: var(--bg);
    border-radius: var(--radius-xs);
    font-size: 13px; line-height: 1.6;
    cursor: pointer;
    transition: all 0.2s;
    max-height: 120px;
    overflow: hidden;
    position: relative;
    margin-bottom: 4px;
}
.note-collapsed-preview:hover { background: #f0e8f0; }
.note-collapsed-preview::after {
    content: '点击展开编辑...';
    position: absolute; bottom: 0; left: 0; right: 0;
    height: 36px;
    background: linear-gradient(transparent, var(--bg));
    display: flex; align-items: flex-end; justify-content: center;
    font-size: 11px; color: var(--text-light); padding-bottom: 4px;
}
.note-collapsed-preview img { max-width: 100%; border-radius: 6px; }
.note-collapsed-preview code { background: #f0f0f5; padding: 1px 4px; border-radius: 3px; font-size: 12px; }
.note-collapsed-preview pre { background: #f0f0f5; padding: 8px; border-radius: 6px; overflow-x: auto; }
.note-collapsed-preview pre code { background: none; }

/* ===== THINK SPACE TAB ===== */
.think-input-area {
    background: var(--card); border-radius: var(--radius);
    padding: 16px 20px; margin-bottom: 20px; box-shadow: var(--shadow);
    border-left: 5px solid var(--secondary);
}
.think-input-area h4 { font-family: var(--font-cute); font-size: 15px; color: var(--secondary); margin-bottom: 10px; }
.think-entry {
    background: var(--card); border-radius: var(--radius);
    padding: 16px 20px; margin-bottom: 12px; box-shadow: var(--shadow);
    border-left: 4px solid var(--secondary-light);
    position: relative;
}
.think-entry-title { font-family: var(--font-cute); font-size: 16px; color: var(--secondary); margin-bottom: 4px; }
.think-entry-time { font-size: 11px; color: var(--text-light); margin-bottom: 8px; }
.think-entry-head { padding-right: 28px; margin-bottom: 8px; }
.think-entry-body { font-size: 14px; line-height: 1.7; }
.think-entry-body img { max-width: 100%; border-radius: var(--radius-xs); }
.think-entry-body code { background: #f0f0f5; padding: 1px 5px; border-radius: 4px; }
.think-entry-body pre { background: #f0f0f5; padding: 12px; border-radius: var(--radius-xs); overflow-x: auto; }
.think-entry-body pre code { background: none; }
.think-entry-delete { position: absolute; top: 10px; right: 12px; background: none; border: none; font-size: 14px; cursor: pointer; color: var(--text-light); opacity: 0; transition: opacity 0.2s; }
.think-entry:hover .think-entry-delete { opacity: 1; }
.think-entry { scroll-margin-top: 88px; }
.think-entry.note-highlight { animation: noteHighlight 1.6s ease; }

/* ===== CATALOG (reused from main site) ===== */
.catalog-card { background: var(--card); border-radius: var(--radius); padding: 14px 20px; margin-bottom: 20px; box-shadow: var(--shadow); border-left: 4px solid var(--warm); }
.catalog-header { display: flex; align-items: center; justify-content: space-between; cursor: pointer; user-select: none; }
.catalog-header h4 { font-family: var(--font-cute); font-size: 15px; color: #F08C28; }
.catalog-caret { font-size: 12px; color: var(--text-light); }
.catalog-body { margin-top: 12px; max-height: 400px; overflow-y: auto; transition: max-height .3s ease, margin-top .3s ease; }
.catalog-body.collapsed { max-height: 0; margin-top: 0; overflow: hidden; }
.catalog-search { width: 100%; padding: 6px 10px; margin-bottom: 10px; border: 1px solid var(--border); border-radius: var(--radius-xs); font-family: var(--font-body); font-size: 12px; color: var(--text); }
.catalog-search:focus { outline: none; border-color: var(--warm); }
.catalog-entry { display: block; padding: 5px 12px; font-size: 13px; color: var(--text); text-decoration: none; border-radius: var(--radius-xs); cursor: pointer; transition: all .15s; margin-bottom: 2px; }
.catalog-entry:hover { background: var(--bg); color: var(--primary); padding-left: 16px; }
@keyframes noteHighlight {
  0%,100% { box-shadow: var(--shadow); border-color: transparent; }
  20%,65% { box-shadow: 0 0 0 4px var(--warm), var(--shadow-hover); border-color: var(--warm); }
}
.think-title-input { width: 100%; padding: 10px 14px; margin-bottom: 10px; border: 2px solid var(--border); border-radius: var(--radius-xs); font-family: var(--font-cute); font-size: 16px; color: var(--secondary); background: #fff; transition: border-color 0.2s; }
.think-title-input:focus { outline: none; border-color: var(--secondary-light); }

/* ===== BG VIEWING MODE ===== */
body.bg-viewing #app, body.bg-viewing #particles { opacity: 0; pointer-events: none; transition: opacity .4s; }
body.bg-viewing #bg-layer.has-bg::after { background: transparent; transition: background .4s; }
body.bg-viewing .bg-view-exit { display: flex; }
.bg-view-exit { display: none; position: fixed; bottom: 32px; left: 50%; transform: translateX(-50%); z-index: 200;
    padding: 12px 28px; background: rgba(0,0,0,.55); backdrop-filter: blur(8px); color: #fff; border: 1px solid rgba(255,255,255,.25);
    border-radius: 28px; font-family: var(--font-cute); font-size: 15px; cursor: pointer; transition: all .25s;
    align-items: center; gap: 8px; }
.bg-view-exit:hover { background: rgba(0,0,0,.75); transform: translateX(-50%) translateY(-2px); }

/* ===== NOTE NAV ===== */
.note-nav { display: flex; flex-direction: column; gap: 4px; }
.note-link { display: block; padding: 7px 12px; border-radius: var(--radius-xs); background: #fff; border: 1px solid var(--border); color: var(--text); text-decoration: none; font-size: 13px; transition: all 0.2s; }
.note-link:hover { background: var(--bg); border-color: var(--primary-light); color: var(--primary); transform: translateX(2px); }

/* ===== SCROLLBAR ===== */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb {
    background: var(--primary-light);
    border-radius: 3px;
}
::-webkit-scrollbar-thumb:hover { background: var(--primary); }

/* ===== RESPONSIVE ===== */
@media (max-width: 768px) {
    .main-layout { flex-direction: column; }
    #sidebar {
        width: 100%; min-width: 100%;
        height: auto; position: relative; top: 0;
        border-right: none;
        border-bottom: 1px solid var(--border);
    }
    .day-nav { grid-template-columns: repeat(4, 1fr); }
    #main-content { padding: 16px; }
    .site-title { font-size: 18px; }
    .header-right { gap: 4px; }
    .header-btn { padding: 6px 8px; font-size: 11px; }
    .header-btn .btn-icon { display: none; }
    .tabs { flex-wrap: wrap; }
    .problem-top { flex-direction: column; align-items: flex-start; }
}