/* ===== Reset & Base ===== */
*,
*::before,
*::after {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

:root {
    --bg-primary: #0a0a0f;
    --bg-sidebar: rgba(255, 255, 255, 0.02);
    --bg-card: rgba(255, 255, 255, 0.03);
    --bg-card-border: rgba(255, 255, 255, 0.05);
    --bg-input: rgba(255, 255, 255, 0.04);
    --bg-input-focus: rgba(255, 255, 255, 0.08);
    --bg-hover: rgba(255, 255, 255, 0.06);

    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-placeholder: #475569;

    --accent: #8b5cf6;
    --accent-hover: #a78bfa;
    --accent-glow: rgba(139, 92, 246, 0.4);
    --accent-secondary: #ec4899;

    --error: #ef4444;
    --success: #10b981;
    --warning: #f59e0b;

    --radius-sm: 10px;
    --radius-md: 16px;
    --transition: 0.3s cubic-bezier(0.25, 0.8, 0.25, 1);
}

/* ===== Light Theme ===== */
[data-theme="light"] {
    --bg-primary: #f8fafc;
    --bg-sidebar: rgba(255, 255, 255, 0.7);
    --bg-card: rgba(255, 255, 255, 0.75);
    --bg-card-border: rgba(0, 0, 0, 0.08);
    --bg-input: rgba(0, 0, 0, 0.03);
    --bg-input-focus: rgba(0, 0, 0, 0.06);
    --bg-hover: rgba(0, 0, 0, 0.05);
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-placeholder: #94a3b8;
    --accent: #6366f1;
    --accent-hover: #4f46e5;
    --accent-glow: rgba(99, 102, 241, 0.3);
    --accent-secondary: #d946ef;
    --error: #ef4444;
    --success: #10b981;
    --warning: #f59e0b;
}

html {
    font-size: 16px;
    -webkit-font-smoothing: antialiased;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    min-height: 100vh;
    display: flex;
    transition: background 0.4s ease, color 0.4s ease;
}

/* ===== Animations ===== */
@keyframes fadeIn {
    from { opacity: 0; transform: translateY(4px); }
    to { opacity: 1; transform: translateY(0); }
}

/* ===== Theme Toggle ===== */
.theme-toggle {
    width: 42px;
    height: 42px;
    border: none;
    border-radius: 50%;
    background: var(--bg-card);
    border: 1px solid var(--bg-card-border);
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    transition: background 0.3s ease, transform 0.3s ease, box-shadow 0.3s ease;
    z-index: 100;
    flex-shrink: 0;
}

.theme-toggle svg {
    width: 20px;
    height: 20px;
    transition: transform 0.4s ease;
}

.theme-toggle:hover {
    transform: scale(1.1);
    box-shadow: 0 4px 16px var(--accent-glow);
}

.theme-toggle:active {
    transform: scale(0.95);
}

.theme-toggle--fixed {
    position: fixed;
    top: 1.25rem;
    right: 1.25rem;
}

/* ===== Settings Placeholder ===== */
.settings-placeholder {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    text-align: center;
    padding: 4rem 2rem;
    animation: fadeIn 0.4s ease both;
}

.settings-placeholder .icon-wrap {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    background: linear-gradient(135deg, rgba(139, 92, 246, 0.15), rgba(236, 72, 153, 0.15));
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
    box-shadow: 0 0 30px var(--accent-glow);
}

.settings-placeholder h2 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.settings-placeholder p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    max-width: 400px;
    line-height: 1.6;
}