:root {
    --bg: #0f1117;
    --surface: #1a1c25;
    --border: #2a2d3a;
    --text: #e4e4e8;
    --text-muted: #9395a5;
    --accent: #7c6cf0;
    --accent-hover: #9589f5;
    --card-hover: #1e2030;
}

[data-theme="light"] {
    --bg: #f5f5f7;
    --surface: #ffffff;
    --border: #dcdce0;
    --text: #1a1c25;
    --text-muted: #6b6d7b;
    --accent: #6555d4;
    --accent-hover: #7c6cf0;
    --card-hover: #f0edff;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.7;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    transition: background 0.2s, color 0.2s;
}

a { color: var(--accent); text-decoration: none; }
a:hover { color: var(--accent-hover); text-decoration: underline; }

/* ── Nav ── */

nav {
    background: var(--surface);
    border-bottom: 1px solid var(--border);
    padding: 0.75rem 1.25rem;
    position: sticky;
    top: 0;
    z-index: 10;
    transition: background 0.2s, border-color 0.2s;
}

nav .container {
    max-width: 720px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 0.5rem;
}

nav .logo {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 700;
    font-size: 1.125rem;
    color: var(--text);
    text-decoration: none;
    flex-shrink: 0;
}

nav .logo:hover { text-decoration: none; }

nav .logo img {
    width: 28px;
    height: 28px;
    border-radius: 6px;
}

[data-theme="light"] nav .logo img { filter: invert(1); }

nav .nav-right {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

nav .links {
    display: none;
    gap: 1.25rem;
}

nav .links a {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.875rem;
    transition: color 0.15s;
}

nav .links a:hover { color: var(--accent-hover); text-decoration: none; }
nav .links a.active { color: var(--accent); }

/* ── Icon buttons (theme + burger) ── */

.icon-btn {
    background: none;
    border: 1px solid var(--border);
    border-radius: 8px;
    padding: 0.35rem;
    cursor: pointer;
    color: var(--text-muted);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.15s;
    width: 32px;
    height: 32px;
}

.icon-btn:hover { color: var(--accent); border-color: var(--accent); }
.icon-btn svg { width: 16px; height: 16px; }

/* Theme toggle icon swap */
.theme-toggle .icon-sun { display: none; }
.theme-toggle .icon-moon { display: block; }
[data-theme="light"] .theme-toggle .icon-sun { display: block; }
[data-theme="light"] .theme-toggle .icon-moon { display: none; }

/* Burger button */
.burger { display: flex; }
.burger .icon-close { display: none; }
.burger.open .icon-menu { display: none; }
.burger.open .icon-close { display: block; }

/* ── Mobile dropdown ── */

.mobile-menu {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
    max-width: 720px;
    margin: 0 auto;
    padding: 0 0;
    overflow: hidden;
    max-height: 0;
    transition: max-height 0.25s ease, padding 0.25s ease;
}

.mobile-menu.open {
    max-height: 200px;
    padding: 0.5rem 0;
}

.mobile-menu a {
    display: block;
    padding: 0.6rem 1rem;
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.925rem;
    border-radius: 8px;
    transition: all 0.15s;
    text-align: right;
}

.mobile-menu a:hover {
    background: var(--card-hover);
    color: var(--text);
    text-decoration: none;
}

.mobile-menu a.active {
    color: var(--accent);
}

/* ── Desktop: show inline links, hide burger ── */

@media (min-width: 540px) {
    nav { padding: 1rem 1.5rem; }
    nav .links { display: flex; }
    .burger { display: none; }
    .mobile-menu { max-height: 0 !important; padding: 0 !important; }
}

/* ── Placeholder badges ── */

.placeholder {
    background: #2a1f3d;
    border: 1px dashed var(--accent);
    border-radius: 4px;
    padding: 0.15rem 0.4rem;
    font-size: 0.85rem;
    color: var(--accent);
}

[data-theme="light"] .placeholder {
    background: #f0edff;
}

/* ── Footer ── */

footer {
    text-align: center;
    padding: 1.5rem;
    color: var(--text-muted);
    font-size: 0.8rem;
    border-top: 1px solid var(--border);
    transition: border-color 0.2s;
}