:root {
    /* ── Existing Base Tokens ── */
    --bg: #f6f7f8;
    --bg-color: #f6f7f8;
    --surface: rgba(255, 255, 255, 0.92);
    --surface-strong: #ffffff;
    --surface-tint: #f1f3f5;
    --surface-dark: #121417;
    --surface-deep: #0a0c0f;
    --line: rgba(18, 20, 23, 0.1);
    --line-strong: rgba(18, 20, 23, 0.18);
    --text: #121417;
    --muted: #66707a;
    --accent: #0f62fe;
    --accent-strong: #0043ce;
    --accent-soft: rgba(15, 98, 254, 0.08);
    --nav-height: 84px;
    --container: min(1180px, calc(100vw - 48px));

    /* ── Material Design 3 Semantic Tokens (Stitch) ── */
    --primary: #0f62fe;
    --on-primary: #ffffff;
    --primary-container: #d6e3ff;
    --secondary: #6366f1;
    --tertiary: #8b5cf6;
    --surface-container: #f0f1f3;
    --surface-container-high: #eaecee;
    --surface-low: #f6f7f8;
    --outline: rgba(18, 20, 23, 0.14);
    --on-surface-variant: #44474e;

    /* ── Spacing Scale ── */
    --spacing-xs: 4px;
    --spacing-sm: 8px;
    --spacing-md: 16px;
    --spacing-lg: 24px;
    --spacing-xl: 32px;
    --spacing-xxl: 56px;

    /* ── Refined Shadows ── */
    --shadow-lg: 0 20px 48px rgba(15, 23, 42, 0.07), 0 8px 16px rgba(15, 23, 42, 0.04);
    --shadow-md: 0 10px 24px rgba(15, 23, 42, 0.05), 0 4px 8px rgba(15, 23, 42, 0.03);
    --shadow-sm: 0 2px 8px rgba(15, 23, 42, 0.04), 0 1px 3px rgba(15, 23, 42, 0.03);

    /* ── Radii ── */
    --radius-xl: 28px;
    --radius-lg: 20px;
    --radius-md: 14px;
    --radius-sm: 8px;
}

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

html {
    scroll-behavior: smooth;
}

html,
body {
    min-height: 100%;
}

body {
    font-family: "Inter", "Avenir Next", "Pretendard Variable", "Segoe UI", sans-serif;
    color: var(--text);
    background:
        radial-gradient(circle at top left, rgba(15, 98, 254, 0.06), transparent 22%),
        linear-gradient(180deg, #fafbfb 0%, #f6f7f8 100%);
    display: flex;
    flex-direction: column;
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    text-rendering: optimizeLegibility;
}

body::before {
    content: "";
    position: fixed;
    inset: 0;
    pointer-events: none;
    background:
        linear-gradient(rgba(15, 23, 42, 0.02) 1px, transparent 1px),
        linear-gradient(90deg, rgba(15, 23, 42, 0.02) 1px, transparent 1px);
    background-size: 40px 40px, 40px 40px;
    mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.08), transparent 85%);
}

a {
    color: inherit;
}

button,
input {
    font: inherit;
}

button {
    color: inherit;
}

#app {
    min-height: 100vh;
}

.content-wrapper {
    flex: 1;
}

h1,
h2,
h3,
h4 {
    font-family: "Inter", "Avenir Next", "Pretendard Variable", "Segoe UI", sans-serif;
    font-weight: 700;
    letter-spacing: -0.035em;
}

p {
    color: var(--muted);
}

.page-shell {
    width: var(--container);
    margin: 0 auto;
    padding: 120px 0 96px; /* increased to prevent overlap with fixed header */
}

.glass-panel {
    background: var(--surface);
    border: 1px solid rgba(255, 255, 255, 0.8);
    box-shadow: var(--shadow-lg);
    backdrop-filter: blur(10px);
}

.section-heading {
    display: flex;
    justify-content: space-between;
    align-items: end;
    gap: 24px;
    margin-bottom: 28px;
}

.section-heading > div {
    display: grid;
    gap: 10px;
}

.section-heading h2 {
    font-size: clamp(2.1rem, 4vw, 3.6rem);
    line-height: 0.98;
}

.section-heading p {
    max-width: 520px;
    font-size: 1rem;
}

.section-kicker {
    font-size: 0.82rem;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--accent-strong);
    font-weight: 700;
}

.soft-card {
    background: linear-gradient(180deg, rgba(255, 255, 255, 0.97), rgba(246, 247, 248, 0.98));
    border: 1px solid rgba(255, 255, 255, 0.92);
    box-shadow: var(--shadow-sm);
}

.slide-panel {
    background: linear-gradient(180deg, #ffffff, var(--surface-tint));
    border: 1px solid rgba(255, 255, 255, 0.94);
    box-shadow: var(--shadow-md);
}

.page-intro {
    display: grid;
    gap: 16px;
    padding: 28px;
    border-radius: var(--radius-xl);
}

.page-intro h1 {
    font-size: clamp(2.6rem, 5vw, 4.8rem);
    line-height: 0.92;
    max-width: 12ch;
}

.page-intro p {
    max-width: 62ch;
    font-size: 1.02rem;
}

@media (max-width: 900px) {
    :root {
        --nav-height: 76px;
        --container: min(100vw - 28px, 1180px);
    }

    .page-shell {
        padding: 100px 0 72px; /* increased to prevent overlap with fixed header on mobile */
    }

    .section-heading {
        flex-direction: column;
        align-items: start;
    }
}