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

:root {
    --bg: #fafafa;
    --surface: #ffffff;
    --text: #1a1a1a;
    --text-secondary: #666666;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --accent-glow: rgba(37, 99, 235, 0.35);
    --border: #e5e5e5;
    --radius: 12px;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.1);
    --transition: 0.25s ease;
    --glass: rgba(255, 255, 255, 0.7);
    --glass-border: rgba(255, 255, 255, 0.3);
}

:root.dark {
    --bg: #0a0a0f;
    --surface: #141420;
    --text: #f0f0f0;
    --text-secondary: #999999;
    --accent: #3b82f6;
    --accent-hover: #60a5fa;
    --accent-glow: rgba(59, 130, 246, 0.4);
    --border: #1e1e2e;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 8px 30px rgba(0, 0, 0, 0.5);
    --glass: rgba(20, 20, 32, 0.7);
    --glass-border: rgba(255, 255, 255, 0.06);
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
    position: relative;
    overflow-x: hidden;
}

/* Study-themed abstract background pattern */
body::before {
    content: '';
    position: fixed;
    inset: 0;
    z-index: -2;
    background:
        /* Floating circles */
        radial-gradient(circle at 15% 20%, var(--accent-glow) 0%, transparent 40%),
        radial-gradient(circle at 85% 15%, rgba(168, 85, 247, 0.12) 0%, transparent 35%),
        radial-gradient(circle at 75% 80%, var(--accent-glow) 0%, transparent 40%),
        radial-gradient(circle at 25% 75%, rgba(236, 72, 153, 0.1) 0%, transparent 35%),
        radial-gradient(circle at 50% 50%, rgba(168, 85, 247, 0.05) 0%, transparent 50%);
    animation: bgShift 20s ease-in-out infinite alternate;
}

body::after {
    content: '';
    position: fixed;
    inset: 0;
    z-index: -1;
    background-image:
        /* Grid dots pattern */
        radial-gradient(circle, var(--border) 1px, transparent 1px);
    background-size: 32px 32px;
    opacity: 0.5;
    mask-image: radial-gradient(ellipse 80% 60% at 50% 50%, black 30%, transparent 70%);
    -webkit-mask-image: radial-gradient(ellipse 80% 60% at 50% 50%, black 30%, transparent 70%);
}

@keyframes bgShift {
    0% { transform: scale(1) rotate(0deg); }
    50% { transform: scale(1.05) rotate(1deg); }
    100% { transform: scale(1) rotate(-1deg); }
}

/* Floating decorative shapes */
.container, .chat-layout, .report-container {
    position: relative;
}

.container {
    max-width: 720px;
    margin: 0 auto;
    padding: 2rem 1.5rem;
    padding-top: 4rem;
    animation: fadeInUp 0.6s ease-out;
}

@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(20px); }
    to { opacity: 1; transform: translateY(0); }
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideInLeft {
    from { opacity: 0; transform: translateX(-20px); }
    to { opacity: 1; transform: translateX(0); }
}

@keyframes pulse-glow {
    0%, 100% { box-shadow: 0 0 15px var(--accent-glow), 0 0 30px transparent; }
    50% { box-shadow: 0 0 20px var(--accent-glow), 0 0 40px var(--accent-glow); }
}

.header {
    text-align: center;
    margin-bottom: 3rem;
    animation: fadeInUp 0.6s ease-out 0.1s both;
}

.header h1 {
    font-size: 2.4rem;
    font-weight: 800;
    letter-spacing: -1px;
    background: linear-gradient(135deg, var(--text) 0%, var(--accent) 50%, var(--text) 100%);
    background-size: 200% 200%;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    animation: shimmer 3s ease-in-out infinite;
}

.header .accent {
    color: var(--accent);
    -webkit-text-fill-color: var(--accent);
    text-shadow: 0 0 20px var(--accent-glow);
}

@keyframes shimmer {
    0%, 100% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
}

.header .subtitle {
    color: var(--text-secondary);
    font-size: 1rem;
    margin-top: 0.4rem;
    letter-spacing: 0.3px;
}

/* JD Section */
.jd-section {
    display: flex;
    flex-direction: column;
    gap: 1rem;
    animation: fadeInUp 0.6s ease-out 0.2s both;
}

textarea {
    width: 100%;
    padding: 1rem;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius);
    background: var(--glass);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    color: var(--text);
    font-family: inherit;
    font-size: 0.9rem;
    resize: vertical;
    transition: border-color var(--transition), box-shadow var(--transition);
}

textarea:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow), var(--shadow);
}

.config-row {
    display: flex;
    gap: 1rem;
}

.config-item {
    flex: 1;
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.config-item label {
    font-size: 0.8rem;
    color: var(--text-secondary);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

select {
    padding: 0.6rem 0.75rem;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius);
    background: var(--glass);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    color: var(--text);
    font-size: 0.9rem;
    cursor: pointer;
    transition: border-color var(--transition), box-shadow var(--transition);
}

select:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.btn-primary {
    padding: 0.9rem 1.8rem;
    background: linear-gradient(135deg, var(--accent), var(--accent-hover));
    color: #ffffff;
    border: none;
    border-radius: var(--radius);
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    position: relative;
    overflow: hidden;
    transition: transform var(--transition), box-shadow var(--transition);
    box-shadow: 0 4px 15px var(--accent-glow);
}

.btn-primary::before {
    content: '';
    position: absolute;
    inset: 0;
    background: linear-gradient(135deg, transparent 30%, rgba(255,255,255,0.2) 50%, transparent 70%);
    background-size: 200% 100%;
    animation: btnShine 2.5s ease-in-out infinite;
}

@keyframes btnShine {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 25px var(--accent-glow), 0 0 40px var(--accent-glow);
}

.btn-primary:active {
    transform: translateY(0);
    box-shadow: 0 2px 10px var(--accent-glow);
}

/* Divider */
.divider {
    display: flex;
    align-items: center;
    margin: 2.5rem 0;
    gap: 1rem;
    animation: fadeIn 0.6s ease-out 0.3s both;
}

.divider::before,
.divider::after {
    content: '';
    flex: 1;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border), transparent);
}

.divider span {
    font-size: 0.85rem;
    color: var(--text-secondary);
    white-space: nowrap;
}

/* Topics Grid */
.topics-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 0.6rem;
    animation: fadeInUp 0.6s ease-out 0.4s both;
}

.topic-btn {
    padding: 0.75rem 0.5rem;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius);
    background: var(--glass);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    color: var(--text);
    font-size: 0.82rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    text-align: center;
    position: relative;
    overflow: hidden;
}

.topic-config {
    display: flex;
    justify-content: center;
    margin-bottom: 1rem;
}

.topic-config select {
    padding: 0.5rem 1rem;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius);
    background: var(--glass);
    color: var(--text);
    font-size: 0.85rem;
    font-weight: 500;
    cursor: pointer;
}

.topic-btn::after {
    content: '';
    position: absolute;
    inset: 0;
    background: radial-gradient(circle at var(--mouse-x, 50%) var(--mouse-y, 50%), var(--accent-glow) 0%, transparent 60%);
    opacity: 0;
    transition: opacity 0.3s ease;
}

.topic-btn:hover::after {
    opacity: 1;
}

.topic-btn:hover {
    border-color: var(--accent);
    color: var(--accent);
    box-shadow: 0 4px 20px var(--accent-glow);
    transform: translateY(-3px) scale(1.02);
}

.topic-btn:active {
    transform: translateY(0) scale(0.98);
}

/* Responsive */
@media (max-width: 600px) {
    .container {
        padding: 1.5rem 1rem;
    }

    .header h1 {
        font-size: 1.6rem;
    }

    .topics-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .config-row {
        flex-direction: column;
    }
}

@media (max-width: 400px) {
    .topics-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

/* Theme Toolbar */
.theme-toolbar {
    position: fixed;
    top: 1rem;
    right: 1rem;
    display: flex;
    gap: 0.4rem;
    z-index: 900;
    animation: fadeIn 0.8s ease-out 0.6s both;
}

.theme-btn {
    width: 38px;
    height: 38px;
    border: 1px solid var(--glass-border);
    border-radius: 50%;
    background: var(--glass);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    cursor: pointer;
    font-size: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: var(--shadow);
    line-height: 1;
    padding: 0;
}

.theme-btn:hover {
    box-shadow: 0 4px 20px var(--accent-glow);
    transform: scale(1.12) rotate(15deg);
    border-color: var(--accent);
}

.theme-color-wrapper {
    position: relative;
}

.color-dropdown {
    position: absolute;
    top: 100%;
    right: 0;
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
    padding: 0.5rem;
    padding-top: 0.85rem;
    background: var(--surface);
    border: 1px solid var(--border);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    opacity: 0;
    pointer-events: none;
    transform: translateY(-4px);
    transition: opacity 0.2s ease, transform 0.2s ease;
}

.theme-color-wrapper:hover .color-dropdown {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
}

.color-swatch {
    width: 26px;
    height: 26px;
    border: 2px solid transparent;
    border-radius: 50%;
    cursor: pointer;
    transition: all var(--transition);
    padding: 0;
}

.color-swatch:hover {
    transform: scale(1.15);
}

.color-swatch.active {
    border-color: var(--text);
    box-shadow: 0 0 0 2px var(--surface), 0 0 0 3px var(--text);
}

/* API Key Modal */
.apikey-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.6);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 1100;
    animation: fadeIn 0.3s ease;
}

.apikey-modal {
    background: var(--glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    padding: 2.5rem;
    max-width: 420px;
    width: 90%;
    text-align: center;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3), 0 0 40px var(--accent-glow);
    animation: modalIn 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

@keyframes modalIn {
    from { opacity: 0; transform: scale(0.9) translateY(20px); }
    to { opacity: 1; transform: scale(1) translateY(0); }
}

.apikey-modal h2 {
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 0.4rem;
}

.apikey-modal p {
    font-size: 0.82rem;
    color: var(--text-secondary);
    margin-bottom: 1.2rem;
}

.apikey-modal a {
    color: var(--accent);
    text-decoration: none;
}

.apikey-modal a:hover {
    text-decoration: underline;
}

.apikey-modal input {
    width: 100%;
    padding: 0.7rem 0.9rem;
    border: 1px solid var(--glass-border);
    border-radius: var(--radius);
    background: var(--glass);
    backdrop-filter: blur(8px);
    -webkit-backdrop-filter: blur(8px);
    color: var(--text);
    font-size: 0.9rem;
    margin-bottom: 1rem;
    font-family: inherit;
    transition: border-color var(--transition), box-shadow var(--transition);
}

.apikey-modal input:focus {
    outline: none;
    border-color: var(--accent);
    box-shadow: 0 0 0 3px var(--accent-glow);
}

.apikey-modal .btn-primary {
    width: 100%;
}

/* ─── History Sidebar ────────────────────────────────────── */

.history-sidebar {
    position: fixed;
    top: 0;
    left: 0;
    width: 320px;
    height: 100vh;
    background: var(--surface);
    border-right: 1px solid var(--border);
    z-index: 1000;
    transform: translateX(-100%);
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-lg);
}

.history-sidebar.open {
    transform: translateX(0);
}

.history-overlay {
    position: fixed;
    inset: 0;
    background: rgba(0, 0, 0, 0.4);
    z-index: 999;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.history-overlay.open {
    opacity: 1;
    pointer-events: auto;
}

.history-header {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 1.25rem 1.25rem 1rem;
    border-bottom: 1px solid var(--border);
}

.history-header h3 {
    font-size: 1rem;
    font-weight: 700;
    color: var(--text);
}

.history-close {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-size: 1.1rem;
    cursor: pointer;
    padding: 0.25rem 0.5rem;
    border-radius: 6px;
    transition: all var(--transition);
}

.history-close:hover {
    color: var(--text);
    background: var(--glass);
}

.history-list {
    flex: 1;
    overflow-y: auto;
    padding: 0.75rem;
}

.history-loading {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.85rem;
    padding: 2rem 0;
}

.history-empty {
    text-align: center;
    color: var(--text-secondary);
    font-size: 0.85rem;
    padding: 3rem 1rem;
    line-height: 1.5;
}

.history-item {
    display: block;
    width: 100%;
    text-align: left;
    padding: 0.85rem 1rem;
    margin-bottom: 0.4rem;
    background: var(--glass);
    border: 1px solid var(--glass-border);
    border-radius: var(--radius);
    cursor: pointer;
    transition: all var(--transition);
    text-decoration: none;
    color: inherit;
}

.history-item:hover {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px var(--accent-glow);
    transform: translateX(2px);
}

.history-item-topic {
    font-size: 0.88rem;
    font-weight: 600;
    color: var(--text);
    margin-bottom: 0.3rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
}

.history-item-meta {
    font-size: 0.75rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 0.6rem;
    flex-wrap: wrap;
}

.history-item-score {
    font-weight: 700;
    color: var(--accent);
}

.history-item-badge {
    display: inline-block;
    padding: 0.1rem 0.45rem;
    font-size: 0.68rem;
    font-weight: 700;
    border-radius: 6px;
    text-transform: uppercase;
}

.history-item-badge.completed {
    background: rgba(34, 197, 94, 0.15);
    color: #22c55e;
}

.history-item-badge.in-progress {
    background: rgba(234, 179, 8, 0.15);
    color: #eab308;
}

@media (max-width: 480px) {
    .history-sidebar {
        width: 85vw;
    }
}