:root {
    color-scheme: dark;
    --bg: oklch(0.185 0.006 250);
    --bg-soft: oklch(0.21 0.006 250);
    --bg-card: oklch(0.225 0.006 250);
    --text: oklch(0.96 0.008 250);
    --text-2: oklch(0.82 0.008 250);
    --muted: oklch(0.62 0.008 250);
    --faint: oklch(0.46 0.008 250);
    --border: oklch(0.28 0.008 250);
    --border-soft: oklch(0.26 0.008 250);
    --accent: oklch(0.65 0.14 250);
    --accent-soft: oklch(0.65 0.14 250 / 0.14);
    --accent-border: oklch(0.65 0.14 250 / 0.35);
    --ok: oklch(0.78 0.13 150);
    --header-bg: oklch(0.185 0.006 250 / 0.88);
    --shadow-sm: 0 1px 2px oklch(0 0 0 / 0.2);
    --shadow-md: 0 4px 16px -2px oklch(0 0 0 / 0.3), 0 2px 6px -1px oklch(0 0 0 / 0.2);
    --shadow-lg: 0 14px 34px -4px oklch(0 0 0 / 0.45), 0 4px 12px -2px oklch(0 0 0 / 0.25);
    --ambient-top: radial-gradient(ellipse 70% 50% at 10% -10%, oklch(0.32 0.05 250 / 0.22), transparent 70%);
    --ambient-side: radial-gradient(ellipse 60% 40% at 92% 5%, oklch(0.65 0.14 250 / 0.08), transparent 60%);
}

:root.light,
html.light,
body.light {
    color-scheme: light;
    --bg: oklch(0.97 0.004 80);
    --bg-soft: oklch(0.94 0.005 80);
    --bg-card: oklch(0.91 0.006 80);
    --text: oklch(0.18 0.01 40);
    --text-2: oklch(0.36 0.008 40);
    --muted: oklch(0.52 0.008 40);
    --faint: oklch(0.66 0.006 40);
    --border: oklch(0.85 0.007 80);
    --border-soft: oklch(0.88 0.006 80);
    --accent: oklch(0.52 0.16 250);
    --accent-soft: oklch(0.52 0.16 250 / 0.1);
    --accent-border: oklch(0.52 0.16 250 / 0.3);
    --ok: oklch(0.5 0.13 150);
    --header-bg: oklch(0.97 0.004 80 / 0.9);
    --shadow-sm: 0 1px 3px oklch(0.18 0.01 40 / 0.05), 0 1px 2px oklch(0.18 0.01 40 / 0.03);
    --shadow-md: 0 4px 16px -2px oklch(0.18 0.01 40 / 0.08), 0 2px 6px -1px oklch(0.18 0.01 40 / 0.04);
    --shadow-lg: 0 14px 34px -4px oklch(0.18 0.01 40 / 0.12), 0 4px 12px -2px oklch(0.18 0.01 40 / 0.05);
    --ambient-top: radial-gradient(ellipse 70% 50% at 10% -10%, oklch(0.92 0.03 250 / 0.55), transparent 70%);
    --ambient-side: radial-gradient(ellipse 60% 40% at 92% 5%, oklch(0.52 0.16 250 / 0.05), transparent 60%);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: 80px;
    overflow-x: clip;
}

body {
    min-height: 100vh;
    overflow-x: clip;
    background-color: var(--bg);
    background-image: var(--ambient-top), var(--ambient-side);
    background-repeat: no-repeat;
    color: var(--text);
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", "SF Pro", "Inter", -apple-system-body, "Helvetica Neue", Helvetica, Arial, sans-serif;
    font-size: 15px;
    letter-spacing: -0.012em;
    -webkit-font-smoothing: antialiased;
}

::selection {
    background: var(--accent);
    color: var(--bg);
}

:focus-visible {
    outline: 2px solid var(--accent);
    outline-offset: 3px;
    border-radius: 6px;
}

a {
    color: inherit;
    text-decoration: none;
    transition: color 150ms ease, border-color 150ms ease, background-color 150ms ease;
}

.container {
    max-width: 1080px;
    margin: 0 auto;
    padding: 0 40px;
}

.topbar {
    position: -webkit-sticky;
    position: sticky;
    top: 0;
    z-index: 100;
    width: 100%;
    backdrop-filter: blur(16px) saturate(180%);
    -webkit-backdrop-filter: blur(16px) saturate(180%);
    background: var(--header-bg);
    border-bottom: 1px solid var(--border-soft);
    box-shadow: 0 4px 20px -2px oklch(0 0 0 / 0.08);
}

.topbar-inner {
    height: 68px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 10px;
}

.brand-mark {
    width: 30px;
    height: 30px;
    border-radius: 6px;
    background: var(--accent);
    color: var(--bg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Display", "SF Pro Text", "SF Pro", "Inter", -apple-system-body, "Helvetica Neue", Helvetica, Arial, sans-serif;
    font-size: 13px;
    font-weight: 700;
    letter-spacing: -0.3px;
}

.brand-name {
    font-size: 14px;
    font-weight: 500;
    color: var(--text);
}

.nav {
    display: flex;
    align-items: center;
    gap: 6px;
    margin-left: auto;
}

.nav a {
    color: var(--text-2);
    font-size: 13px;
    font-weight: 500;
    padding: 6px 12px;
    border-radius: 8px;
    border: 1px solid transparent;
    transition: color 150ms ease, border-color 150ms ease, background-color 150ms ease, box-shadow 150ms ease;
}

.nav a:hover {
    color: var(--text);
    border-color: var(--border-soft);
    background: var(--bg-soft);
}

.nav a.active,
.nav a[aria-current="page"] {
    color: var(--text);
    border-color: var(--border-soft);
    background: var(--bg-soft);
    box-shadow: var(--shadow-sm);
}

.menu-toggle {
    display: none;
    width: 34px;
    height: 34px;
    border-radius: 8px;
    border: 1px solid var(--border-soft);
    background: var(--bg-soft);
    box-shadow: var(--shadow-sm);
    cursor: pointer;
    align-items: center;
    justify-content: center;
    color: var(--text-2);
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
    transition: transform 160ms ease, border-color 160ms ease, background-color 160ms ease, box-shadow 160ms ease, color 160ms ease;
}

.menu-toggle:hover {
    border-color: var(--accent-border);
    color: var(--text);
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
}

.menu-toggle svg {
    width: 15px;
    height: 15px;
}

.theme-toggle {
    width: 34px;
    height: 34px;
    border-radius: 8px;
    border: 1px solid var(--border-soft);
    background: var(--bg-soft);
    box-shadow: var(--shadow-sm);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    position: relative;
    color: var(--text-2);
    touch-action: manipulation;
    -webkit-tap-highlight-color: transparent;
    overflow: visible;
    transition: transform 160ms ease, border-color 160ms ease, color 160ms ease, background-color 160ms ease, box-shadow 160ms ease;
}

.theme-toggle:hover {
    border-color: var(--accent-border);
    color: var(--text);
    box-shadow: var(--shadow-md);
    transform: translateY(-1px);
}

.theme-toggle:active {
    transform: scale(0.94);
}

.theme-fx-wave {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 32px;
    height: 32px;
    margin-left: -16px;
    margin-top: -16px;
    border-radius: 50%;
    pointer-events: none;
    transform: scale(0);
    opacity: 0;
    z-index: 10;
    will-change: transform, opacity;
}

.theme-toggle.anim-put-out-light .theme-fx-wave {
    border: 2px solid rgba(251, 191, 36, 0.9);
    box-shadow: 0 0 16px 3px rgba(251, 191, 36, 0.7), inset 0 0 12px rgba(251, 191, 36, 0.6);
    background: radial-gradient(circle, rgba(254, 240, 138, 0.95) 0%, rgba(251, 191, 36, 0.6) 45%, transparent 70%);
    animation: putOutLightFlare 0.55s cubic-bezier(0.16, 1, 0.3, 1) forwards;
}

@keyframes putOutLightFlare {
    0% {
        transform: scale(0.4);
        opacity: 1;
    }
    60% {
        opacity: 0.85;
    }
    100% {
        transform: scale(2.2);
        opacity: 0;
    }
}

.theme-toggle.anim-put-out-light {
    border-color: rgba(251, 191, 36, 0.85);
    box-shadow: 0 0 16px -2px rgba(251, 191, 36, 0.55);
}

.theme-toggle.anim-take-light-in .theme-fx-wave {
    border: 1.5px solid rgba(147, 197, 253, 0.85);
    box-shadow: 0 0 20px 4px rgba(59, 130, 246, 0.55), inset 0 0 12px rgba(147, 197, 253, 0.4);
    background: radial-gradient(circle, rgba(224, 242, 254, 0.85) 0%, rgba(59, 130, 246, 0.6) 50%, transparent 75%);
    animation: takeLightInVortex 0.62s cubic-bezier(0.22, 1, 0.36, 1) forwards;
}

@keyframes takeLightInVortex {
    0% {
        transform: scale(2.3);
        opacity: 0;
    }
    20% {
        opacity: 0.95;
    }
    70% {
        opacity: 0.85;
        transform: scale(0.65);
    }
    100% {
        transform: scale(0.12);
        opacity: 0;
    }
}

.theme-toggle.anim-take-light-in {
    border-color: rgba(96, 165, 250, 0.85);
    box-shadow: 0 0 16px -1px rgba(59, 130, 246, 0.5);
}

.theme-toggle svg {
    width: 14px;
    height: 14px;
    position: absolute;
    transition: opacity 160ms ease, transform 200ms cubic-bezier(0.16, 1, 0.3, 1);
}

.theme-icon-sun {
    opacity: 0;
    transform: scale(0.65) rotate(-35deg);
}

.theme-icon-moon {
    opacity: 1;
    transform: scale(1) rotate(0deg);
}

html.light .theme-icon-sun,
body.light .theme-icon-sun {
    opacity: 1;
    transform: scale(1) rotate(0deg);
}

html.light .theme-icon-moon,
body.light .theme-icon-moon {
    opacity: 0;
    transform: scale(0.65) rotate(35deg);
}

.footer {
    padding: 40px 0 60px;
    border-top: 1px solid var(--border-soft);
    display: flex;
    justify-content: space-between;
    gap: 12px;
    flex-wrap: wrap;
    color: var(--faint);
    font-family: -apple-system, BlinkMacSystemFont, "SF Pro Text", "SF Pro Display", "SF Pro", "Inter", -apple-system-body, "Helvetica Neue", Helvetica, Arial, sans-serif;
    font-size: 11.5px;
}

.footer a:hover {
    color: var(--text);
}

@media (max-width: 760px) {
    .container {
        padding: 0 18px;
    }

    .topbar-inner {
        min-height: 70px;
        padding: 14px 18px;
        flex-wrap: nowrap;
        gap: 12px;
    }

    .nav {
        display: none;
        position: absolute;
        top: 76px;
        left: 18px;
        right: 18px;
        margin: 0;
        padding: 16px 14px 18px;
        flex-direction: column;
        align-items: center;
        gap: 8px;
        background: var(--header-bg);
        border: 1px solid var(--border-soft);
        border-radius: 10px;
        box-shadow: 0 12px 28px oklch(0.08 0 0 / 0.18);
    }

    .nav.is-open {
        display: flex;
    }

    .nav a {
        text-align: center;
        width: 100%;
        padding: 8px 12px;
        border-radius: 8px;
    }

    .theme-toggle {
        margin-left: auto;
    }

    .menu-toggle {
        display: inline-flex;
        margin-left: 8px;
    }
}

@media (max-width: 520px) {
    .brand-name {
        font-size: 13px;
    }

    .nav a {
        font-size: 14px;
    }
}

/* Reduced Motion Handling Across Site */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }

    html {
        scroll-behavior: auto !important;
    }

    .theme-toggle.anim-put-out-light,
    .theme-toggle.anim-take-light-in,
    .theme-toggle.anim-put-out-light .theme-fx-wave,
    .theme-toggle.anim-take-light-in .theme-fx-wave {
        animation: none !important;
    }

    .theme-toggle svg {
        transition: none !important;
    }

    .project-card:hover,
    .writing-card:hover,
    .writing-featured:hover,
    .contact-card:hover,
    .filter-chip:hover,
    .btn-primary:hover,
    .writing-featured:hover .writing-preview img,
    .blog-card:hover {
        transform: none !important;
    }
}