:root {
    --bg-body: #f8f9fb;
    --bg-surface: #ffffff;
    --text-primary: #111827;
    --text-secondary: #4b5563;
    --text-muted: #9ca3af;
    --border-light: #f3f4f6;
    --border-default: #e5e7eb;
    --bg-input: #f9fafb;
    --bg-hover: #f3f4f6;
    --bg-muted: #e5e7eb;
    --accent: #6366f1;
    --accent-hover: #4f46e5;
    --accent-subtle: #eef2ff;
    --accent-glow: rgba(99, 102, 241, 0.15);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.08);
    --shadow-xl: 0 24px 64px rgba(0, 0, 0, 0.12);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 20px;
}

:root[data-theme="dark"] {
    --bg-body: #09090b;
    --bg-surface: #18181b;
    --text-primary: #f4f4f5;
    --text-secondary: #a1a1aa;
    --text-muted: #52525b;
    --border-light: #27272a;
    --border-default: #3f3f46;
    --bg-input: #1c1c22;
    --bg-hover: #303036;
    --bg-muted: #27272a;
    --accent: #818cf8;
    --accent-hover: #6366f1;
    --accent-subtle: rgba(99, 102, 241, 0.08);
    --accent-glow: rgba(129, 140, 248, 0.12);
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
    --shadow-lg: 0 12px 40px rgba(0, 0, 0, 0.5);
    --shadow-xl: 0 24px 64px rgba(0, 0, 0, 0.6);
}

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

html {
    scrollbar-gutter: stable;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', system-ui, sans-serif;
    background: var(--bg-body);
    color: var(--text-primary);
    min-height: 100vh;
    min-height: 100dvh;
    transition: background 0.15s ease, color 0.15s ease;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    padding-top: env(safe-area-inset-top);
    padding-bottom: env(safe-area-inset-bottom);
    padding-left: env(safe-area-inset-left);
    padding-right: env(safe-area-inset-right);
}

button {
    padding: 10px 18px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    font-family: inherit;
}

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

.btn-primary:hover:not(:disabled) {
    background: var(--accent-hover);
    box-shadow: 0 2px 8px var(--accent-glow);
}

.btn-primary:active:not(:disabled) {
    box-shadow: none;
}

.btn-primary:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.btn-secondary {
    background: var(--bg-surface);
    color: var(--text-secondary);
    border: 1px solid var(--border-default);
}

.btn-secondary:hover {
    background: var(--bg-hover);
    border-color: var(--text-muted);
}

.hidden {
    display: none !important;
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

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

@keyframes modalIn {
    from { opacity: 0; transform: scale(0.98) translateY(4px); }
    to { opacity: 1; transform: scale(1) translateY(0); }
}

@keyframes dropIn {
    from { opacity: 0; transform: translateY(-4px); }
    to { opacity: 1; transform: translateY(0); }
}

:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

button:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 2px;
}

.icon-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-sm);
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s ease, background 0.2s ease;
}

.icon-btn:hover {
    color: var(--text-primary);
    background: var(--bg-hover);
}

@media (max-width: 640px) {
    .icon-btn {
        width: 44px;
        height: 44px;
    }
}