/* EcWhite — Premium B2B Whitening Brand System
   White + silver packaging language. Controlled, not decorative. */

:root {
  --ink: #1a1d21;
  --ink-soft: #3d4450;
  --ink-muted: #6b7380;
  --silver: #9aa3ad;
  --silver-light: #c5ccd4;
  --silver-line: #d8dee6;
  --bg: #f7f8fa;
  --bg-soft: #eef1f4;
  --white: #ffffff;
  --border: #e2e6eb;
  --radius: 16px;
  --radius-sm: 10px;
  --shadow: 0 8px 28px -10px rgba(26, 29, 33, 0.10);
  --shadow-soft: 0 4px 16px -6px rgba(26, 29, 33, 0.08);
}

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

html {
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  background: var(--bg);
  color: var(--ink);
  line-height: 1.65;
  font-size: 16px;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

img { max-width: 100%; height: auto; display: block; }
a { color: inherit; text-decoration: none; }
ul { list-style: none; }

.container {
  max-width: 1080px;
  margin: 0 auto;
  padding: 0 24px;
}

.container--narrow {
  max-width: 680px;
}

/* Typography */
h1, h2, h3 {
  font-weight: 700;
  letter-spacing: -0.035em;
  line-height: 1.22;
  color: var(--ink);
}

h1 {
  font-size: clamp(1.9rem, 4.2vw, 2.85rem);
}

h2 {
  font-size: clamp(1.55rem, 3.2vw, 2.15rem);
  margin-bottom: 0.5em;
}

h3 {
  font-size: 1.05rem;
  margin-bottom: 0.4em;
  letter-spacing: -0.02em;
}

p {
  color: var(--ink-soft);
}

.lead {
  font-size: 1.1rem;
  line-height: 1.6;
}

.tm {
  font-size: 0.52em;
  font-weight: 700;
  vertical-align: super;
  margin-left: 0.1em;
  letter-spacing: 0.02em;
}

.label {
  display: inline-block;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--silver);
  margin-bottom: 12px;
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 24px;
  border-radius: var(--radius-sm);
  font-size: 0.95rem;
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: transform 0.18s ease, box-shadow 0.18s ease, background 0.18s ease;
  text-decoration: none;
  line-height: 1.2;
}

.btn-primary {
  background: linear-gradient(180deg, #2e333a 0%, #1a1d21 100%);
  color: #fff;
  box-shadow: 0 2px 8px rgba(26, 29, 33, 0.22);
}

.btn-primary:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 14px rgba(26, 29, 33, 0.28);
  color: #fff;
}

.btn-secondary {
  background: var(--white);
  color: var(--ink);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-soft);
}

.btn-secondary:hover {
  border-color: var(--silver-light);
  transform: translateY(-1px);
}

.btn-lg {
  padding: 15px 28px;
  font-size: 1rem;
}

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(247, 248, 250, 0.92);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}

.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 68px;
}

.logo {
  display: flex;
  align-items: center;
  gap: 12px;
}

.logo-mark {
  width: 40px;
  height: 40px;
  object-fit: contain;
  border-radius: 9px;
  background: var(--white);
  border: 1px solid var(--silver-line);
  padding: 3px;
  flex-shrink: 0;
}

.logo-text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand-name {
  font-weight: 700;
  font-size: 1.05rem;
  letter-spacing: -0.03em;
  color: var(--ink);
}

.brand-tag {
  font-size: 0.65rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--silver);
}

.nav {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav a {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--ink-soft);
  transition: color 0.15s;
}

.nav a:hover {
  color: var(--ink);
}

.nav .btn {
  margin-left: 8px;
  padding: 10px 18px;
  font-size: 0.88rem;
}

.nav .btn-primary,
.nav .btn-primary:hover {
  color: #fff;
}

.mobile-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.4rem;
  color: var(--ink);
  cursor: pointer;
  padding: 8px;
}

/* Hero */
.hero {
  padding: 64px 0 72px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: 48px;
  align-items: center;
}

.hero-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 12px;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 999px;
  font-size: 0.72rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 20px;
}

.hero h1 {
  margin-bottom: 18px;
}

.hero-lead {
  font-size: 1.08rem;
  color: var(--ink-soft);
  margin-bottom: 28px;
  max-width: 38em;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 28px;
}

.hero-signals {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.hero-signals span {
  font-size: 0.8rem;
  font-weight: 500;
  color: var(--ink-muted);
  padding: 5px 12px;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 999px;
}

.hero-visual {
  display: flex;
  justify-content: center;
}

.product-frame {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: 20px;
  padding: 16px;
  box-shadow: var(--shadow);
  max-width: 420px;
  width: 100%;
}

.product-frame img {
  border-radius: 12px;
  width: 100%;
  aspect-ratio: 2/3;
  object-fit: cover;
}

/* Sections */
.section {
  padding: 72px 0;
}

.section--alt {
  background: var(--white);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.section-header {
  margin-bottom: 40px;
  max-width: 640px;
}

.section-header p {
  margin-top: 8px;
  font-size: 1.05rem;
}

/* Range */
.range-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.range-card {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 24px;
  transition: border-color 0.18s, box-shadow 0.18s;
}

.range-card:hover {
  border-color: var(--silver-light);
  box-shadow: var(--shadow-soft);
}

.range-card h3 {
  margin-bottom: 8px;
}

.range-card p {
  font-size: 0.95rem;
}

/* Why */
.why-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 20px;
}

.why-card {
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px 26px;
}

.why-card h3 {
  margin-bottom: 10px;
}

.why-card p {
  font-size: 0.95rem;
}

/* Process */
.process-list {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 16px;
  counter-reset: step;
}

.process-item {
  position: relative;
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 24px 20px;
}

.process-item::before {
  counter-increment: step;
  content: counter(step);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 28px;
  height: 28px;
  background: var(--ink);
  color: #fff;
  font-size: 0.8rem;
  font-weight: 700;
  border-radius: 50%;
  margin-bottom: 14px;
}

.process-item h3 {
  font-size: 0.98rem;
  margin-bottom: 6px;
}

.process-item p {
  font-size: 0.88rem;
  line-height: 1.55;
}

/* Contact */
.contact-grid {
  display: grid;
  grid-template-columns: 1fr 1.15fr;
  gap: 48px;
  align-items: start;
}

.contact-intro h2 {
  margin-bottom: 12px;
}

.contact-intro p {
  margin-bottom: 20px;
}

.contact-note {
  font-size: 0.9rem;
  color: var(--ink-muted);
  padding: 14px 16px;
  background: var(--bg);
  border-radius: var(--radius-sm);
  border: 1px solid var(--border);
}

.form {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 32px 28px;
  box-shadow: var(--shadow-soft);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
  margin-bottom: 16px;
}

.form-group {
  margin-bottom: 16px;
}

.form-group label {
  display: block;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--ink);
  margin-bottom: 6px;
}

.form-group input,
.form-group select,
.form-group textarea {
  width: 100%;
  padding: 11px 14px;
  font-size: 0.95rem;
  font-family: inherit;
  color: var(--ink);
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: 8px;
  transition: border-color 0.15s, box-shadow 0.15s;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--silver);
  box-shadow: 0 0 0 3px rgba(154, 163, 173, 0.18);
  background: var(--white);
}

.form-group textarea {
  min-height: 110px;
  resize: vertical;
}

.form-submit {
  margin-top: 8px;
  width: 100%;
}

.form-hint {
  margin-top: 12px;
  font-size: 0.82rem;
  color: var(--ink-muted);
  text-align: center;
}

/* FAQ */
.faq-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.faq-item {
  background: var(--white);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 20px 22px;
}

.faq-item h3 {
  font-size: 0.98rem;
  margin-bottom: 8px;
}

.faq-item p {
  font-size: 0.92rem;
  line-height: 1.55;
}

/* Footer */
.site-footer {
  padding: 48px 0 32px;
  border-top: 1px solid var(--border);
  background: var(--white);
}

.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 32px;
  margin-bottom: 32px;
}

.footer-brand p {
  margin-top: 12px;
  font-size: 0.9rem;
  max-width: 320px;
}

.footer-links {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
}

.footer-links a {
  font-size: 0.88rem;
  color: var(--ink-soft);
  font-weight: 500;
}

.footer-links a:hover {
  color: var(--ink);
}

.footer-bottom {
  padding-top: 24px;
  border-top: 1px solid var(--border);
  font-size: 0.82rem;
  color: var(--ink-muted);
}

.footer-bottom a {
  color: var(--ink-soft);
}

/* Responsive */
@media (max-width: 900px) {
  .hero-grid {
    grid-template-columns: 1fr;
    gap: 40px;
  }

  .hero-visual {
    order: -1;
  }

  .product-frame {
    max-width: 320px;
  }

  .range-grid {
    grid-template-columns: 1fr;
  }

  .why-grid {
    grid-template-columns: 1fr;
  }

  .process-list {
    grid-template-columns: 1fr 1fr;
  }

  .contact-grid {
    grid-template-columns: 1fr;
    gap: 32px;
  }
}

@media (max-width: 680px) {
  .nav {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    background: var(--white);
    border-bottom: 1px solid var(--border);
    flex-direction: column;
    padding: 16px 24px 24px;
    gap: 4px;
    box-shadow: var(--shadow);
  }

  .nav.open {
    display: flex;
  }

  .nav a {
    padding: 12px 0;
    font-size: 1rem;
  }

  .nav .btn {
    margin: 12px 0 0;
    width: 100%;
  }

  .mobile-toggle {
    display: block;
  }

  .hero {
    padding: 40px 0 56px;
  }

  .section {
    padding: 56px 0;
  }

  .process-list {
    grid-template-columns: 1fr;
  }

  .form-row {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    flex-direction: column;
  }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .btn, .range-card { transition: none; }
}