/* ============================================
   SUMBULBS Corporate Website - Main Stylesheet
   ============================================ */

:root {
  --primary: #0B2545;
  --primary-2: #13315C;
  --primary-3: #1B4079;
  --accent: #F5A623;
  --accent-2: #FFD166;
  --bg: #ffffff;
  --bg-alt: #F5F7FB;
  --bg-dark: #0B2545;
  --text: #1a1a1a;
  --text-light: #ffffff;
  --muted: #6B7280;
  --border: #E5E7EB;
  --shadow-sm: 0 1px 2px rgba(11,37,69,.06);
  --shadow: 0 4px 16px rgba(11,37,69,.08);
  --shadow-lg: 0 12px 40px rgba(11,37,69,.12);
  --radius: 10px;
  --radius-lg: 16px;
  --maxw: 1200px;
  --header-h: 72px;
  --font: "Inter", "PingFang SC", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }
body {
  font-family: var(--font);
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--primary); text-decoration: none; transition: color .2s; }
a:hover { color: var(--accent); }
img { max-width: 100%; display: block; }
h1, h2, h3, h4 { color: var(--primary); margin: 0 0 .5em; line-height: 1.25; font-weight: 600; }
h1 { font-size: clamp(1.9rem, 3.6vw, 3rem); }
h2 { font-size: clamp(1.5rem, 2.6vw, 2.2rem); }
h3 { font-size: 1.2rem; }
p { margin: 0 0 1em; }

/* ============ Layout ============ */
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 24px; }
section { padding: 72px 0; }
section.alt { background: var(--bg-alt); }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 48px; }
.section-head .eyebrow {
  display: inline-block; color: var(--accent); font-weight: 600; font-size: .85rem;
  letter-spacing: .12em; text-transform: uppercase; margin-bottom: 10px;
}
.section-head p { color: var(--muted); font-size: 1.05rem; }

/* ============ Header / Nav ============ */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255,255,255,.92);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--border);
  height: var(--header-h);
}
.nav {
  display: flex; align-items: center; justify-content: space-between;
  height: 100%; max-width: var(--maxw); margin: 0 auto; padding: 0 24px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; color: var(--primary); }
.brand img { height: 36px; }
.brand-name { font-size: 1.1rem; letter-spacing: .04em; }
.nav-links { display: flex; gap: 28px; list-style: none; padding: 0; margin: 0; }
.nav-links a {
  color: var(--text); font-weight: 500; font-size: .95rem;
  padding: 8px 0; position: relative;
}
.nav-links a:hover, .nav-links a.active { color: var(--primary); }
.nav-links a.active::after {
  content: ""; position: absolute; left: 0; right: 0; bottom: 0; height: 2px;
  background: var(--accent); border-radius: 2px;
}
.lang-toggle {
  border: 1px solid var(--border); background: #fff; color: var(--primary);
  padding: 6px 14px; border-radius: 999px; font-weight: 600; font-size: .85rem;
  cursor: pointer; transition: all .2s;
}
.lang-toggle:hover { border-color: var(--primary); background: var(--primary); color: #fff; }
.nav-toggle {
  display: none; background: none; border: 0; cursor: pointer;
  width: 40px; height: 40px; padding: 0;
}
.nav-toggle span { display: block; height: 2px; background: var(--primary); margin: 6px 8px; border-radius: 2px; transition: .2s; }

/* ============ Buttons ============ */
.btn {
  display: inline-block; padding: 12px 26px; border-radius: 999px; font-weight: 600;
  font-size: .95rem; border: 1px solid transparent; cursor: pointer; transition: all .2s;
  text-align: center;
}
.btn-primary { background: var(--accent); color: #1a1a1a; }
.btn-primary:hover { background: #ff8a00; color: #fff; transform: translateY(-1px); box-shadow: var(--shadow); }
.btn-ghost { background: transparent; color: #fff; border-color: rgba(255,255,255,.5); }
.btn-ghost:hover { background: #fff; color: var(--primary); }
.btn-outline { background: transparent; color: var(--primary); border-color: var(--primary); }
.btn-outline:hover { background: var(--primary); color: #fff; }

/* ============ Hero ============ */
.hero {
  position: relative; color: #fff; padding: 120px 0 100px;
  background:
    linear-gradient(135deg, rgba(11,37,69,.92) 0%, rgba(19,49,92,.86) 100%),
    radial-gradient(ellipse at top right, rgba(245,166,35,.25), transparent 60%),
    var(--primary);
  overflow: hidden;
}
.hero::before {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background-image:
    linear-gradient(rgba(255,255,255,.04) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255,255,255,.04) 1px, transparent 1px);
  background-size: 48px 48px;
  mask-image: radial-gradient(ellipse at center, black 30%, transparent 75%);
}
.hero .container { position: relative; }
.hero h1 { color: #fff; }
.hero .lead { font-size: 1.15rem; color: rgba(255,255,255,.85); max-width: 640px; margin-bottom: 32px; }
.hero-cta { display: flex; gap: 14px; flex-wrap: wrap; }
.hero-stats {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 24px; margin-top: 56px;
  padding-top: 40px; border-top: 1px solid rgba(255,255,255,.15);
}
.hero-stat .num { font-size: 2rem; font-weight: 700; color: var(--accent); }
.hero-stat .lbl { font-size: .9rem; color: rgba(255,255,255,.75); }

/* ============ Cards / Grids ============ */
.grid { display: grid; gap: 24px; }
.grid-2 { grid-template-columns: repeat(2, 1fr); }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }

.card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px; transition: all .25s;
}
.card:hover { box-shadow: var(--shadow-lg); transform: translateY(-3px); border-color: transparent; }
.card .icon {
  width: 48px; height: 48px; border-radius: 10px;
  background: linear-gradient(135deg, var(--primary), var(--primary-3));
  color: #fff; display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem; font-weight: 700; margin-bottom: 16px;
}
.card h3 { margin-bottom: 8px; }
.card p { color: var(--muted); font-size: .95rem; margin: 0; }

.product-card {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  overflow: hidden; transition: all .25s; display: flex; flex-direction: column;
}
.product-card:hover { box-shadow: var(--shadow-lg); transform: translateY(-3px); }
.product-card .thumb {
  aspect-ratio: 4/3; background: var(--bg-alt);
  display: flex; align-items: center; justify-content: center;
  border-bottom: 1px solid var(--border);
}
.product-card .thumb img { width: 100%; height: 100%; object-fit: cover; }
.product-card .body { padding: 20px; flex: 1; display: flex; flex-direction: column; }
.product-card h3 { margin-bottom: 6px; font-size: 1.05rem; }
.product-card p { color: var(--muted); font-size: .9rem; flex: 1; }

/* ============ Applications ============ */
.apps-grid {
  display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 16px;
}
.app-chip {
  background: #fff; border: 1px solid var(--border); border-radius: var(--radius);
  padding: 18px 14px; text-align: center; font-size: .92rem; color: var(--text);
  transition: all .2s;
}
.app-chip:hover { border-color: var(--accent); background: #fffbf2; }
.app-chip .ico { font-size: 1.5rem; margin-bottom: 6px; }

/* ============ Certifications ============ */
.certs { display: flex; flex-wrap: wrap; gap: 12px; justify-content: center; }
.cert-badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 10px 18px; border: 1.5px solid var(--primary); color: var(--primary);
  border-radius: 999px; font-weight: 600; font-size: .9rem;
  background: #fff;
}
.cert-badge::before { content: "✓"; color: var(--accent); font-weight: 700; }

/* ============ CTA Banner ============ */
.cta-banner {
  background: linear-gradient(135deg, var(--primary), var(--primary-2));
  color: #fff; border-radius: var(--radius-lg);
  padding: 48px; display: flex; align-items: center; justify-content: space-between;
  gap: 24px; flex-wrap: wrap;
}
.cta-banner h2 { color: #fff; margin: 0 0 6px; }
.cta-banner p { color: rgba(255,255,255,.8); margin: 0; }

/* ============ Process Steps ============ */
.process { counter-reset: step; }
.process .step {
  display: flex; gap: 20px; padding: 20px 0; border-bottom: 1px dashed var(--border);
}
.process .step:last-child { border-bottom: 0; }
.process .step::before {
  counter-increment: step; content: counter(step);
  flex-shrink: 0; width: 36px; height: 36px; border-radius: 50%;
  background: var(--accent); color: var(--primary); display: flex;
  align-items: center; justify-content: center; font-weight: 700; font-size: .95rem;
}
.process .step h4 { margin: 0 0 2px; color: var(--text); font-size: 1rem; }
.process .step p { margin: 0; color: var(--muted); font-size: .92rem; }

/* ============ Contact ============ */
.contact-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 48px; align-items: start; }
.contact-info { display: flex; flex-direction: column; gap: 16px; }
.contact-info .item {
  display: flex; gap: 14px; align-items: flex-start;
  padding: 14px 0; border-bottom: 1px solid var(--border);
}
.contact-info .item:last-child { border-bottom: 0; }
.contact-info .ico {
  width: 40px; height: 40px; border-radius: 8px; flex-shrink: 0;
  background: var(--bg-alt); color: var(--primary);
  display: flex; align-items: center; justify-content: center; font-weight: 700;
}
.contact-info .lbl { font-size: .82rem; color: var(--muted); text-transform: uppercase; letter-spacing: .08em; }
.contact-info .val { font-size: 1rem; color: var(--text); }

form { display: grid; gap: 14px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
label { font-size: .85rem; color: var(--muted); font-weight: 500; display: block; margin-bottom: 6px; }
input, textarea, select {
  width: 100%; padding: 11px 14px; font-size: .95rem;
  border: 1px solid var(--border); border-radius: 8px;
  background: #fff; color: var(--text); font-family: inherit;
  transition: border-color .2s, box-shadow .2s;
}
input:focus, textarea:focus, select:focus {
  outline: none; border-color: var(--primary);
  box-shadow: 0 0 0 3px rgba(11,37,69,.08);
}
textarea { min-height: 130px; resize: vertical; }
.form-note { font-size: .8rem; color: var(--muted); }

/* ============ Footer ============ */
.site-footer { background: var(--bg-dark); color: rgba(255,255,255,.7); padding: 56px 0 24px; }
.footer-grid { display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 36px; margin-bottom: 36px; }
.footer-grid h4 { color: #fff; font-size: .95rem; margin-bottom: 14px; letter-spacing: .04em; }
.footer-grid a { color: rgba(255,255,255,.7); display: block; padding: 4px 0; font-size: .9rem; }
.footer-grid a:hover { color: var(--accent); }
.footer-brand p { font-size: .9rem; max-width: 320px; }
.socials { display: flex; gap: 10px; margin-top: 16px; flex-wrap: wrap; }
.socials a {
  width: 38px; height: 38px; border-radius: 50%;
  background: rgba(255,255,255,.08); display: flex; align-items: center; justify-content: center;
  padding: 0; color: #fff; transition: all .2s;
}
.socials a:hover { background: var(--accent); color: var(--primary); transform: translateY(-2px); }
.copyright {
  border-top: 1px solid rgba(255,255,255,.1); padding-top: 20px;
  text-align: center; font-size: .82rem; color: rgba(255,255,255,.5);
}

/* ============ Page Hero (sub pages) ============ */
.page-hero {
  background: linear-gradient(135deg, var(--primary), var(--primary-2));
  color: #fff; padding: 80px 0 60px; text-align: center;
}
.page-hero h1 { color: #fff; margin-bottom: 10px; }
.page-hero p { color: rgba(255,255,255,.8); max-width: 600px; margin: 0 auto; font-size: 1.05rem; }

/* ============ Toast / Notice ============ */
.notice {
  display: none; padding: 14px 18px; border-radius: 8px;
  background: #ecfdf5; color: #065f46; border: 1px solid #a7f3d0; font-size: .92rem;
}
.notice.show { display: block; }

/* ============ Responsive ============ */
@media (max-width: 960px) {
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .contact-grid { grid-template-columns: 1fr; }
  .hero-stats { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 720px) {
  section { padding: 56px 0; }
  .nav-links {
    display: none; position: absolute; top: var(--header-h); left: 0; right: 0;
    background: #fff; flex-direction: column; padding: 16px 24px;
    border-bottom: 1px solid var(--border); gap: 6px;
  }
  .nav-links.open { display: flex; }
  .nav-toggle { display: block; }
  .grid-2, .grid-3, .grid-4 { grid-template-columns: 1fr; }
  .footer-grid { grid-template-columns: 1fr; }
  .form-row { grid-template-columns: 1fr; }
  .cta-banner { padding: 32px; }
  .hero { padding: 80px 0 64px; }
  .hero-stats { grid-template-columns: 1fr 1fr; gap: 16px; }
  .hero-stat .num { font-size: 1.5rem; }
}