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


:root {
    --A_bg:    #EAF1FA;
    --A_text:  #1A2A45;
    --B_bg:    #2A4A80;
    --B_text:  #EAF1FA;
    --card_bg: #F0F6FF;
    --muted:   #A8C4EE;
    --dividers:#C5D9F2;
    --links:   #4A7AB5;
    --border:  #2a2a2a;
    --accent1: #E8C87A;
    --accent2: #D64E4E;       
    --accent3: #3A9E78;       

    --serif:   'DM Serif Display', Georgia, serif;
    --sans:    'DM Sans', system-ui, sans-serif;
    --nav-h:   64px;
}

html {
    scroll-behavior: smooth;
    background: var(--A_bg);
    color: var(--B_bg);
    font-family: var(--sans);
    font-weight: 300;
}

.theme-light {
    --section-bg: var(--A_bg);
    --section-text: var(--A_text);
    --section-accent: var(--B_bg);
    --border: var(--dividers);
}

.theme-dark {
    --section-bg: var(--B_bg);
    --section-text: var(--B_text);
    --section-accent: var(--muted);
    --border: rgba(255,255,255,0.12);
}

/* ── Scrollbar ────────────────────────────────── */
::-webkit-scrollbar { width: 0px; }

/* ── Nav ──────────────────────────────────────── */
nav {
    position: fixed;
    top: 0; left: 0; right: 0;
    height: var(--nav-h);
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 48px;
    background: var(--card_bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border);
    transition: border-color 0.3s;
}

.nav-logo {
    font-family: var(--serif);
    font-size: 1.25rem;
    color: var(--B_bg);
    letter-spacing: 0.02em;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-swap {
  position: relative;
  width: 28px;
  height: 28px;
  flex-shrink: 0;
  transition: transform 0.4s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.logo-swap svg {
  position: absolute;
  top: 0; left: 0;
  width: 100%; height: 100%;
  transition: opacity 0.35s ease;
}

.logo-swap .logo-hover       { opacity: 0; }
.nav-logo:hover .logo-default { opacity: 0; }
.nav-logo:hover .logo-hover   { opacity: 1; }
.nav-logo:hover .logo-swap    { transform: scale(1.08); }

.nav-links {
    display: flex;
    gap: 40px;
    list-style: none;
}

.nav-links a {
    font-size: 0.78rem;
    font-weight: 500;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    color: var(--links);
    text-decoration: none;
    position: relative;
    padding-bottom: 4px;
    transition: color 0.25s;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0; left: 0;
    width: 0; height: 1px;
    background: var(--accent);
    transition: width 0.3s ease;
}

.nav-links a:hover,
.nav-links a.active { color: var(--A_text); }
.nav-links a:hover::after,
.nav-links a.active::after { width: 100%; }

/* Hamburger (mobile) */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
    background: none;
    border: none;
    padding: 4px;
}
.hamburger span {
    display: block;
    width: 24px; height: 2px;
    background: var(--A_text);
    transition: all 0.3s;
}

/* ── Shared section structure ─────────────────────────────────── */
section {
    min-height: 100vh;
    padding: calc(var(--nav-h) + 80px) 48px 80px;
    display: flex;
    flex-direction: column;
    justify-content: center;
    border-bottom: 1px solid var(--border);
    position: relative;
    overflow: hidden;
}

.section-label {
    font-size: 0.7rem;
    font-weight: 500;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    margin-bottom: 24px;
    display: flex;
    align-items: center;
    gap: 12px;
}
.section-label::before {
    content: '';
    display: block;
    width: 32px; height: 1px;
    background: var(--section-text);
}

h1, h2 {
    font-family: var(--serif);
    line-height: 1.1;
}

/* ── Buttons ───────────────────────────────────── */
.btn {
    display: inline-block;
    padding: 14px 36px;
    border: 1px solid var(--border);
    color: var(--A_bg);
    font-family: var(--sans);
    font-size: 0.78rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    text-decoration: none;
    transition: background 0.25s, color 0.25s;
}
.btn:hover { background: var(--muted); color: var(--border); }

.btn-ghost {
    margin-left: 16px;
    border-color: var(--border);
    color: var(--links);
}
.btn-ghost:hover { background: var(--muted); color: var(--A_text); }

/* ── Footer ───────────────────────────────────── */
footer {
    text-align: left;
    color: var(--card_bg);
}