:root {
  --bg: #0b0f1a;
  --bg-soft: #111827;
  --card: #151d2e;
  --card-hover: #1a2438;
  --border: #253048;
  --text: #e8edf7;
  --muted: #93a0b8;
  --accent: #6366f1;
  --accent-2: #22d3ee;
  --green: #34d399;
  --red: #f87171;
  --amber: #fbbf24;
  --radius: 14px;
}

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

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}

.container { max-width: 1100px; margin: 0 auto; padding: 0 24px; }
.hidden { display: none !important; }
.center { text-align: center; margin-top: 28px; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(11, 15, 26, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav { display: flex; align-items: center; justify-content: space-between; height: 64px; }
.logo { font-size: 22px; font-weight: 800; color: var(--text); text-decoration: none; letter-spacing: -0.5px; }
.logo span { background: linear-gradient(90deg, var(--accent), var(--accent-2)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.nav-links { display: flex; align-items: center; gap: 22px; }
.nav-links a { color: var(--muted); text-decoration: none; font-size: 15px; font-weight: 500; }
.nav-links a:hover { color: var(--text); }

/* Buttons */
.btn {
  display: inline-block; padding: 12px 24px; border-radius: 10px; border: none; cursor: pointer;
  background: linear-gradient(90deg, var(--accent), #8b5cf6);
  color: #fff !important; font-weight: 600; font-size: 15px; text-decoration: none;
  transition: transform 0.15s, box-shadow 0.15s;
}
.btn:hover { transform: translateY(-1px); box-shadow: 0 8px 24px rgba(99, 102, 241, 0.35); }
.btn-sm { padding: 8px 16px; font-size: 14px; }
.btn-ghost { background: transparent; border: 1px solid var(--border); color: var(--text) !important; }
.btn-ghost:hover { box-shadow: none; border-color: var(--accent); }

/* Hero */
.hero { padding: 96px 0 72px; text-align: center; background: radial-gradient(ellipse 70% 50% at 50% -10%, rgba(99, 102, 241, 0.25), transparent); }
.eyebrow { color: var(--accent-2); font-weight: 600; font-size: 14px; text-transform: uppercase; letter-spacing: 1.5px; margin-bottom: 14px; }
.hero h1 { font-size: clamp(32px, 5.5vw, 56px); line-height: 1.12; font-weight: 800; letter-spacing: -1.5px; max-width: 780px; margin: 0 auto; }
.grad { background: linear-gradient(90deg, var(--accent), var(--accent-2)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.sub { color: var(--muted); font-size: 18px; max-width: 640px; margin: 20px auto 0; }
.hero-cta { margin-top: 32px; display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.stats { display: flex; gap: 56px; justify-content: center; margin-top: 64px; flex-wrap: wrap; }
.stat strong { display: block; font-size: 34px; font-weight: 800; background: linear-gradient(90deg, var(--accent), var(--accent-2)); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat span { color: var(--muted); font-size: 14px; }

/* Sections */
.section { padding: 64px 0; }
.section h2 { font-size: 30px; font-weight: 800; letter-spacing: -0.5px; margin-bottom: 8px; }
.section-sub { color: var(--muted); margin-bottom: 24px; }
.section h2 + .grid, .section h2 + .plans { margin-top: 28px; }

/* Cards */
.grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 18px; }
.card {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 24px; text-decoration: none; color: var(--text); display: block;
  transition: transform 0.15s, border-color 0.15s, background 0.15s;
}
.card:hover { transform: translateY(-3px); border-color: var(--accent); background: var(--card-hover); }
.card .icon { font-size: 30px; margin-bottom: 12px; }
.card h3 { font-size: 17px; font-weight: 700; margin-bottom: 6px; line-height: 1.35; }
.card p { color: var(--muted); font-size: 14px; }
.card .kicker { font-size: 12.5px; font-weight: 600; color: var(--accent-2); text-transform: uppercase; letter-spacing: 1px; margin-bottom: 8px; }
.card-foot { display: flex; gap: 8px; margin-top: 14px; flex-wrap: wrap; }

.chip {
  display: inline-block; font-size: 12px; font-weight: 600; padding: 3px 10px; border-radius: 999px;
  background: rgba(99, 102, 241, 0.15); color: #a5b4fc; border: 1px solid rgba(99, 102, 241, 0.3);
}
.chip.cyan { background: rgba(34, 211, 238, 0.12); color: #67e8f9; border-color: rgba(34, 211, 238, 0.3); }
.chip.green { background: rgba(52, 211, 153, 0.12); color: var(--green); border-color: rgba(52, 211, 153, 0.3); }
.chip.amber { background: rgba(251, 191, 36, 0.12); color: var(--amber); border-color: rgba(251, 191, 36, 0.3); }
.chip.red { background: rgba(248, 113, 113, 0.12); color: var(--red); border-color: rgba(248, 113, 113, 0.3); }

/* Pricing */
.plans { display: grid; grid-template-columns: repeat(auto-fit, minmax(260px, 340px)); gap: 20px; justify-content: center; }
.plan { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 32px; position: relative; }
.plan.featured { border-color: var(--accent); box-shadow: 0 0 40px rgba(99, 102, 241, 0.2); }
.plan .badge { position: absolute; top: -12px; right: 20px; background: linear-gradient(90deg, var(--accent), var(--accent-2)); color: #fff; font-size: 12px; font-weight: 700; padding: 4px 12px; border-radius: 999px; }
.plan h3 { font-size: 19px; }
.plan .price { font-size: 40px; font-weight: 800; margin: 10px 0 2px; }
.plan .price small { font-size: 15px; color: var(--muted); font-weight: 500; }
.plan ul { list-style: none; margin: 20px 0 24px; }
.plan li { color: var(--muted); font-size: 14.5px; padding: 6px 0 6px 26px; position: relative; }
.plan li::before { content: "✓"; position: absolute; left: 0; color: var(--green); font-weight: 700; }
.plan .btn { width: 100%; text-align: center; }

/* Cert page */
.cert-head { padding: 64px 0 8px; background: radial-gradient(ellipse 70% 60% at 50% -20%, rgba(34, 211, 238, 0.15), transparent); }
.cert-head h1 { font-size: clamp(26px, 4vw, 40px); font-weight: 800; letter-spacing: -1px; }
.cert-head .sub { margin: 12px 0 0; max-width: 720px; }
.meta-row { display: flex; gap: 10px; margin-top: 18px; flex-wrap: wrap; }

/* Questions */
.qlist { display: flex; flex-direction: column; gap: 18px; max-width: 820px; margin: 0 auto; }
.qcard { background: var(--card); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px; }
.qcard .qtop { display: flex; gap: 8px; align-items: center; margin-bottom: 14px; flex-wrap: wrap; }
.qcard .qnum { color: var(--muted); font-size: 13px; font-weight: 700; }
.qcard .qtext { font-size: 16.5px; font-weight: 600; line-height: 1.5; }
.options { display: flex; flex-direction: column; gap: 10px; margin-top: 18px; }
.opt {
  text-align: left; background: var(--bg-soft); border: 1px solid var(--border); color: var(--text);
  padding: 13px 16px; border-radius: 10px; cursor: pointer; font-size: 15px; line-height: 1.45;
  transition: border-color 0.12s, background 0.12s;
}
.opt:hover:not(:disabled) { border-color: var(--accent); }
.opt:disabled { cursor: default; opacity: 0.85; }
.opt.correct { border-color: var(--green); background: rgba(52, 211, 153, 0.1); }
.opt.wrong { border-color: var(--red); background: rgba(248, 113, 113, 0.08); }
.explain { margin-top: 16px; padding: 14px 16px; border-left: 3px solid var(--accent-2); background: rgba(34, 211, 238, 0.06); border-radius: 0 10px 10px 0; color: var(--muted); font-size: 14.5px; }
.explain strong { color: var(--accent-2); }

/* Locked question */
.qcard.locked { position: relative; overflow: hidden; }
.qcard.locked .qtext { filter: blur(0px); color: var(--muted); }
.lockbox {
  margin-top: 16px; padding: 20px; border: 1px dashed var(--border); border-radius: 10px;
  text-align: center; background: rgba(99, 102, 241, 0.05);
}
.lockbox p { color: var(--muted); font-size: 14.5px; margin-bottom: 14px; }
.lockbox .lock { font-size: 22px; display: block; margin-bottom: 6px; }

/* Footer */
.site-footer { border-top: 1px solid var(--border); padding: 32px 0; margin-top: 40px; }
.site-footer p { color: var(--muted); font-size: 13.5px; }

@media (max-width: 640px) {
  .nav-links { gap: 14px; }
  .nav-links a:not(.btn) { display: none; }
  .stats { gap: 32px; }
  .hero { padding: 64px 0 48px; }
}

/* ===== Phase 4: forms, tables, admin ===== */
.muted { color: var(--muted); }
.ok { color: var(--green); }
.bad { color: var(--red); }

.panel {
  background: var(--card); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 22px;
}
.panel label { display: block; color: var(--muted); font-size: 14px; margin-bottom: 12px; }
.panel input, .panel select, .panel textarea,
.inline-form input, .inline-form select {
  display: block; width: 100%; margin-top: 5px;
  background: var(--bg-soft); border: 1px solid var(--border); border-radius: 8px;
  color: var(--text); padding: 10px 12px; font-size: 15px; font-family: inherit;
}
.panel input:focus, .panel select:focus, .panel textarea:focus { outline: none; border-color: var(--accent); }
.panel input[type="radio"], .panel input[type="checkbox"] { display: inline-block; width: auto; margin: 0; }

.inline-form { display: flex; gap: 12px; align-items: flex-end; flex-wrap: wrap; }
.inline-form label { display: flex; flex-direction: column; margin-bottom: 0; font-size: 13px; color: var(--muted); }
.inline-form input, .inline-form select { margin-top: 4px; width: auto; min-width: 110px; }

.btn-danger { background: transparent; border: 1px solid rgba(248,113,113,0.5); color: var(--red) !important; }
.btn-danger:hover { box-shadow: none; border-color: var(--red); background: rgba(248,113,113,0.08); }

.notice { padding: 12px 16px; border-radius: 10px; font-size: 14.5px; margin: 14px 0; border: 1px solid var(--border); background: var(--card); }
.notice.green { border-color: rgba(52,211,153,0.4); color: var(--green); background: rgba(52,211,153,0.07); }
.notice.red { border-color: rgba(248,113,113,0.4); color: var(--red); background: rgba(248,113,113,0.07); }
.notice.amber { border-color: rgba(251,191,36,0.4); color: var(--amber); background: rgba(251,191,36,0.07); }
.notice a { color: inherit; }

.tablewrap { overflow-x: auto; margin-top: 20px; border: 1px solid var(--border); border-radius: var(--radius); }
table { width: 100%; border-collapse: collapse; background: var(--card); font-size: 14px; }
th { text-align: left; padding: 12px 14px; color: var(--muted); font-weight: 600; border-bottom: 1px solid var(--border); white-space: nowrap; }
td { padding: 12px 14px; border-bottom: 1px solid var(--border); vertical-align: top; }
tr:last-child td { border-bottom: none; }

.admin-nav { display: flex; gap: 6px; flex-wrap: wrap; margin: 18px 0 26px; }
.admin-nav a {
  color: var(--muted); text-decoration: none; font-size: 14px; font-weight: 600;
  padding: 8px 14px; border: 1px solid var(--border); border-radius: 999px;
}
.admin-nav a:hover { color: var(--text); border-color: var(--accent); }

.opt.guess { border-color: var(--accent-2); background: rgba(34,211,238,0.08); }

/* ===== Phase 5: light theme ===== */
:root[data-theme="light"] {
  --bg: #f4f6fb;
  --bg-soft: #eaeef6;
  --card: #ffffff;
  --card-hover: #f7f9ff;
  --border: #dce2ee;
  --text: #10182b;
  --muted: #5a6478;
}
:root[data-theme="light"] .site-header { background: rgba(255, 255, 255, 0.88); }
:root[data-theme="light"] .hero { background: radial-gradient(ellipse 70% 50% at 50% -10%, rgba(99, 102, 241, 0.14), transparent); }
:root[data-theme="light"] .cert-head { background: radial-gradient(ellipse 70% 60% at 50% -20%, rgba(34, 211, 238, 0.10), transparent); }
:root[data-theme="light"] .chip { color: #4f46e5; }
:root[data-theme="light"] .plan.featured { box-shadow: 0 0 30px rgba(99, 102, 241, 0.15); }
.theme-btn {
  background: transparent; border: 1px solid var(--border); border-radius: 999px;
  width: 36px; height: 36px; cursor: pointer; font-size: 16px; line-height: 1;
  display: inline-flex; align-items: center; justify-content: center;
}
.theme-btn:hover { border-color: var(--accent); }

/* ===== Phase 5: images ===== */
.cover-img { width: 100%; max-height: 220px; object-fit: cover; border-radius: 10px; margin-bottom: 14px; border: 1px solid var(--border); }
.q-img { max-width: 100%; max-height: 320px; border-radius: 10px; border: 1px solid var(--border); margin-top: 12px; }
.opt-img { display: block; max-width: 220px; max-height: 140px; border-radius: 8px; margin-top: 8px; }
.thumb { width: 54px; height: 38px; object-fit: cover; border-radius: 6px; border: 1px solid var(--border); }

/* ===== Phase 5: impersonation banner ===== */
.imp-banner {
  background: linear-gradient(90deg, #b45309, #d97706); color: #fff; text-align: center;
  padding: 8px 16px; font-size: 14px; font-weight: 600;
}
.imp-banner a { color: #fff; text-decoration: underline; }

/* ===== Phase 5: live chat widget ===== */
.chat-fab {
  position: fixed; right: 22px; bottom: 22px; z-index: 90;
  width: 58px; height: 58px; border-radius: 50%; border: none; cursor: pointer;
  background: linear-gradient(135deg, var(--accent), #8b5cf6);
  color: #fff; font-size: 24px; box-shadow: 0 10px 30px rgba(99, 102, 241, 0.45);
  display: flex; align-items: center; justify-content: center;
  transition: transform 0.15s;
}
.chat-fab:hover { transform: scale(1.06); }
.chat-badge {
  position: absolute; top: -3px; right: -3px; background: var(--red); color: #fff;
  font-size: 11px; font-weight: 700; min-width: 20px; height: 20px; border-radius: 999px;
  display: flex; align-items: center; justify-content: center; padding: 0 5px;
}
.chat-panel {
  position: fixed; right: 22px; bottom: 22px; z-index: 95;
  width: min(360px, calc(100vw - 32px)); height: min(520px, calc(100vh - 90px));
  background: var(--card); border: 1px solid var(--border); border-radius: 16px;
  display: flex; flex-direction: column; overflow: hidden;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.35);
}
.chat-head {
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 16px; background: linear-gradient(135deg, var(--accent), #8b5cf6); color: #fff;
}
.chat-head strong { font-size: 16px; }
.chat-sub { font-size: 12px; opacity: 0.85; }
.chat-close { background: none; border: none; color: #fff; font-size: 16px; cursor: pointer; padding: 4px 8px; }
.chat-msgs { flex: 1; overflow-y: auto; padding: 14px; display: flex; flex-direction: column; gap: 8px; background: var(--bg); }
.chat-msg {
  max-width: 82%; padding: 9px 13px; border-radius: 14px; font-size: 14px; line-height: 1.45;
  white-space: pre-wrap; word-break: break-word;
}
.chat-msg.agent { align-self: flex-start; background: var(--card); border: 1px solid var(--border); color: var(--text); border-bottom-left-radius: 4px; }
.chat-msg.mine { align-self: flex-end; background: var(--accent); color: #fff; border-bottom-right-radius: 4px; }
.chat-form { display: flex; gap: 8px; padding: 10px; border-top: 1px solid var(--border); background: var(--card); }
.chat-input {
  flex: 1; resize: none; background: var(--bg-soft); color: var(--text);
  border: 1px solid var(--border); border-radius: 10px; padding: 9px 12px; font-size: 14px; font-family: inherit;
}
.chat-input:focus { outline: none; border-color: var(--accent); }
.chat-send {
  background: var(--accent); color: #fff; border: none; border-radius: 10px;
  padding: 0 16px; font-weight: 600; font-size: 14px; cursor: pointer;
}

/* support console */
.support-msgs { height: 420px; overflow-y: auto; padding: 14px; display: flex; flex-direction: column; gap: 8px; background: var(--bg); border: 1px solid var(--border); border-radius: 12px; }
.chat-row-unread { font-weight: 700; }