/* ── Design Tokens ──────────────────────────────────────── */
:root,
[data-theme="light"] {
    --bg: #f7f7f7;
    --text: #1a1a1a;
    --muted: #6b7280;
    --card: #ffffff;
    --accent: #8b5cf6;
    --accent-hover: #7c3aed;

    --font-body: 'Space Grotesk', 'Helvetica Neue', sans-serif;

    /* Fluid type scale */
    --text-xs: clamp(0.75rem, 0.7rem + 0.25vw, 0.875rem);
    --text-sm: clamp(0.875rem, 0.8rem + 0.35vw, 1rem);
    --text-base: clamp(1rem, 0.95rem + 0.25vw, 1.125rem);
    --text-lg: clamp(1.125rem, 1rem + 0.75vw, 1.5rem);
    --text-xl: clamp(1.5rem, 1.2rem + 1.25vw, 2.25rem);
    --text-2xl: clamp(2rem, 1.2rem + 2.5vw, 3.5rem);
    --text-3xl: clamp(2.5rem, 1rem + 4vw, 5rem);

    /* 4px spacing system */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;

    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-full: 9999px;

    --transition-base: 200ms cubic-bezier(0.16, 1, 0.3, 1);
    --transition-theme: 350ms cubic-bezier(0.4, 0, 0.2, 1);

    --shadow-sm: 0 1px 3px rgba(26, 26, 26, 0.08);
    --shadow-md: 0 4px 16px rgba(26, 26, 26, 0.10);
}


[data-theme="dark"] {
    --bg: #0f0f14;
    --text: #f5f5f5;
    --muted: #a1a1aa;
    --card: #1a1a1a;
    --accent: #a78bfa;
    --accent-hover: #c4b5fd;

    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.30);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.40);
}


@media (prefers-color-scheme: dark) {
    :root:not([data-theme]) {
        --bg: #0f0f14;
        --text: #f5f5f5;
        --muted: #a1a1aa;
        --card: #1a1a1a;
        --accent: #a78bfa;
        --accent-hover: #c4b5fd;
        --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.30);
        --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.40);
    }
}


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


html {
    height: 100%;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    scroll-behavior: smooth;
}


body {
    height: 100%;
    overflow: hidden;
    display: flex;
    flex-direction: column;
    font-family: var(--font-body);
    font-size: var(--text-base);
    color: var(--text);
    background-color: var(--bg);
    line-height: 1.6;
    transition:
        background-color var(--transition-theme),
        color var(--transition-theme);
}


img,
svg {
    display: block;
    max-width: 100%;
}


button {
    cursor: pointer;
    background: none;
    border: none;
    font: inherit;
    color: inherit;
}


::selection {
    background: rgba(139, 92, 246, 0.18);
    color: var(--text);
}


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


.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}


@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        transition-duration: 0.01ms !important;
    }
}


/* ── Header ─────────────────────────────────────────────── */
.site-header {
    flex-shrink: 0;
    padding: var(--space-4) var(--space-4);
    /* mobile */
}


.header-inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    max-width: 760px;
    margin-inline: auto;
}


.header-name {
    font-size: var(--text-sm);
    font-weight: 600;
    letter-spacing: -0.01em;
    color: var(--text);
    transition: color var(--transition-theme);
}


/* ── Theme Toggle ───────────────────────────────────────── */
.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: var(--radius-full);
    color: var(--muted);
    transition:
        color var(--transition-base),
        background-color var(--transition-base);
}


.theme-toggle:hover {
    color: var(--text);
    background-color: rgba(139, 92, 246, 0.08);
}


/* Icon visibility logic */
[data-theme="light"] .icon-sun {
    display: none;
}

[data-theme="light"] .icon-moon {
    display: block;
}

[data-theme="dark"] .icon-moon {
    display: none;
}

[data-theme="dark"] .icon-sun {
    display: block;
}


@media (prefers-color-scheme: light) {
    :root:not([data-theme]) .icon-sun {
        display: none;
    }

    :root:not([data-theme]) .icon-moon {
        display: block;
    }
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme]) .icon-sun {
        display: block;
    }

    :root:not([data-theme]) .icon-moon {
        display: none;
    }
}


/* ── Hero Section ───────────────────────────────────────── */
main {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}


.hero {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--space-6) var(--space-4);
    /* mobile */
}


.hero-inner {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    max-width: 640px;
    width: 100%;
    animation: heroEntrance 600ms cubic-bezier(0.16, 1, 0.3, 1) both;
}


@keyframes heroEntrance {
    from {
        opacity: 0;
        transform: translateY(20px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}


.hero-name {
    font-size: var(--text-3xl);
    font-weight: 700;
    letter-spacing: -0.04em;
    line-height: 1.05;
    margin-bottom: var(--space-4);

    background: linear-gradient(120deg,
            #8b5cf6 0%,
            #8b5cf6 25%,
            #e0d4ff 50%,
            #8b5cf6 75%,
            #8b5cf6 100%);
    background-size: 250% 100%;
    background-position: 100% center;
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;

    animation: heroShimmer 3.5s ease-in-out infinite;
    animation-delay: 0.8s;
}


@keyframes heroShimmer {

    0%,
    100% {
        background-position: 100% center;
    }

    50% {
        background-position: 0% center;
    }
}


.hero-title {
    font-size: var(--text-lg);
    font-weight: 500;
    color: var(--muted);
    letter-spacing: -0.01em;
    margin-bottom: var(--space-6);
    transition: color var(--transition-theme);
}


.hero-tagline {
    font-size: var(--text-base);
    font-weight: 400;
    font-style: italic;
    color: var(--muted);
    line-height: 1.75;
    max-width: 44ch;
    margin-bottom: var(--space-10);
    transition: color var(--transition-theme);
}


/* ── CTA Button ─────────────────────────────────────────── */
.cta-btn {
    display: inline-flex;
    align-items: center;
    padding: var(--space-3) var(--space-8);
    font-family: var(--font-body);
    font-size: var(--text-sm);
    font-weight: 600;
    letter-spacing: 0.01em;
    color: var(--accent);
    border: 1.5px solid var(--accent);
    border-radius: var(--radius-full);
    text-decoration: none;
    transition:
        color var(--transition-base),
        background-color var(--transition-base),
        border-color var(--transition-base),
        transform var(--transition-base),
        box-shadow var(--transition-base);
}


.cta-btn:hover,
.cta-btn:focus-visible {
    color: #ffffff;
    background-color: var(--accent);
    border-color: var(--accent);
    transform: translateY(-2px);
    box-shadow: 0 8px 24px rgba(139, 92, 246, 0.28);
}


.cta-btn:active {
    transform: translateY(0);
    box-shadow: none;
}


/* ── Links Section ──────────────────────────────────────── */
.links {
    flex-shrink: 0;
    padding: var(--space-6) var(--space-4) var(--space-8);
    /* mobile */
}


.links-inner {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-8);
    /* mobile: tighter */
    max-width: 400px;
    margin-inline: auto;
}


.link-icon {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 52px;
    height: 52px;
    border-radius: var(--radius-full);
    color: var(--muted);
    text-decoration: none;
    background-color: var(--card);
    border: 1.5px solid rgba(139, 92, 246, 0.15);
    transition:
        color var(--transition-base),
        border-color var(--transition-base),
        background-color var(--transition-base),
        transform var(--transition-base),
        box-shadow var(--transition-base);
}


.link-icon:hover,
.link-icon:focus-visible {
    color: var(--accent);
    border-color: var(--accent);
    background-color: rgba(139, 92, 246, 0.06);
    transform: translateY(-4px);
    box-shadow: 0 8px 20px rgba(139, 92, 246, 0.18);
}


.link-icon:active {
    transform: translateY(-2px);
}


/* ── Responsive ─────────────────────────────────────────── */
@media (min-width: 768px) {
    .site-header {
        padding: var(--space-8) var(--space-12);
    }

    .header-inner {
        max-width: 900px;
    }

    .hero {
        padding: var(--space-8);
    }

    .hero-inner {
        max-width: 700px;
    }

    .links {
        padding: var(--space-8) var(--space-6) var(--space-10);
    }

    .links-inner {
        gap: var(--space-12);
    }
}