/* ============ Header ============ */
.header { position: fixed; top: 0; left: 0; right: 0; z-index: 100; padding-block: 20px; transition: all var(--transition); border-bottom: 1px solid transparent; }
.header.scrolled { padding-block: 13px; background: rgba(10,10,10,.86); backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px); border-bottom-color: var(--line); }
[data-theme="light"] .header.scrolled { background: rgba(255,255,255,.9); }
.header-inner { position: relative; display: flex; align-items: center; justify-content: space-between; gap: 24px; }
.logo { font-family: var(--ff-mono); font-size: 1.05rem; font-weight: 700; letter-spacing: -.01em; }
.logo .blink { color: var(--amber); animation: blink 1.1s step-end infinite; }
.nav { display: flex; align-items: center; gap: 32px; }
.nav a { font-family: var(--ff-mono); font-size: .82rem; text-transform: uppercase; letter-spacing: .04em; color: var(--text-dim); transition: color var(--transition), border-color var(--transition); padding-bottom: 3px; border-bottom: 1px solid transparent; }
.nav a:hover, .nav a.active { color: var(--text); border-color: var(--amber); }
.nav-actions { display: flex; align-items: center; gap: 14px; }
.theme-toggle { width: 36px; height: 36px; border: 1px solid var(--line-strong); border-radius: var(--radius-sm); display: flex; align-items: center; justify-content: center; font-size: 1rem; transition: border-color var(--transition); }
.theme-toggle:hover { border-color: var(--amber); }
.nav-toggle { display: none; flex-direction: column; justify-content: center; gap: 5px; width: 30px; height: 30px; }
.nav-toggle span { display: block; width: 100%; height: 2px; background: var(--text); transition: all var(--transition); }
.nav-toggle.active span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.active span:nth-child(2) { opacity: 0; }
.nav-toggle.active span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

@keyframes blink { 0%, 50% { opacity: 1; } 51%, 100% { opacity: 0; } }