/* ===========================
   DESIGN TOKENS
   =========================== */

:root {
  /* Typography */
  --font-display: 'DM Serif Display', Georgia, serif;
  --font-body: 'DM Sans', 'Helvetica Neue', sans-serif;

  --text-xs:   clamp(0.75rem,  0.7rem  + 0.25vw, 0.875rem);
  --text-sm:   clamp(0.875rem, 0.8rem  + 0.35vw, 1rem);
  --text-base: clamp(1rem,     0.95rem + 0.25vw, 1.125rem);
  --text-lg:   clamp(1.125rem, 1rem    + 0.75vw, 1.5rem);
  --text-xl:   clamp(1.5rem,   1.2rem  + 1.25vw, 2.25rem);
  --text-2xl:  clamp(2rem,     1.2rem  + 2.5vw,  3.5rem);
  --text-3xl:  clamp(2.5rem,   1rem    + 4vw,    5rem);

  /* Spacing */
  --space-1:  0.25rem;
  --space-2:  0.5rem;
  --space-3:  0.75rem;
  --space-4:  1rem;
  --space-5:  1.25rem;
  --space-6:  1.5rem;
  --space-8:  2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --space-24: 6rem;
  --space-32: 8rem;

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;

  --transition-interactive: 180ms cubic-bezier(0.16, 1, 0.3, 1);
  --content-narrow: 640px;
  --content-default: 960px;
  --content-wide: 1200px;
}

/* ===========================
   LIGHT MODE (default)
   =========================== */
:root, [data-theme="light"] {
  --color-bg:             #f8f7f4;
  --color-surface:        #ffffff;
  --color-surface-2:      #f2f1ee;
  --color-surface-offset: #edecea;
  --color-divider:        #e0ddd8;
  --color-border:         #d4d1ca;

  --color-text:           #1a1a1a;
  --color-text-muted:     #6b6b6b;
  --color-text-faint:     #a0a0a0;

  /* Teal accent — medical, trustworthy */
  --color-primary:        #0a7e7e;
  --color-primary-hover:  #065e5e;
  --color-primary-active: #044a4a;
  --color-primary-light:  #e6f5f5;

  --color-success:        #2d8a4e;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.06);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.08);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.10);
}

/* ===========================
   DARK MODE
   =========================== */
[data-theme="dark"] {
  --color-bg:             #111110;
  --color-surface:        #1a1918;
  --color-surface-2:      #222120;
  --color-surface-offset: #1d1c1b;
  --color-divider:        #2a2928;
  --color-border:         #383736;

  --color-text:           #e8e7e5;
  --color-text-muted:     #8a8987;
  --color-text-faint:     #5a5957;

  --color-primary:        #4dbfbf;
  --color-primary-hover:  #3aa3a3;
  --color-primary-active: #2d8888;
  --color-primary-light:  #1a2e2e;

  --color-success:        #5dba7d;

  --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
  --shadow-lg: 0 12px 32px rgba(0,0,0,0.5);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --color-bg:             #111110;
    --color-surface:        #1a1918;
    --color-surface-2:      #222120;
    --color-surface-offset: #1d1c1b;
    --color-divider:        #2a2928;
    --color-border:         #383736;
    --color-text:           #e8e7e5;
    --color-text-muted:     #8a8987;
    --color-text-faint:     #5a5957;
    --color-primary:        #4dbfbf;
    --color-primary-hover:  #3aa3a3;
    --color-primary-active: #2d8888;
    --color-primary-light:  #1a2e2e;
    --color-success:        #5dba7d;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.4);
    --shadow-lg: 0 12px 32px rgba(0,0,0,0.5);
  }
}

/* ===========================
   HEADER
   =========================== */
.header {
  position: sticky;
  top: 0;
  z-index: 50;
  background: color-mix(in srgb, var(--color-bg) 90%, transparent);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border-bottom: 1px solid transparent;
  transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1),
              box-shadow 0.3s cubic-bezier(0.16, 1, 0.3, 1),
              border-color 0.3s ease;
}
.header--scrolled {
  border-bottom-color: var(--color-divider);
  box-shadow: var(--shadow-sm);
}
.header--hidden {
  transform: translateY(-100%);
}

.header-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  padding: var(--space-4) var(--space-6);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-6);
}

.logo {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  font-family: var(--font-display);
  font-size: var(--text-lg);
  color: var(--color-text);
  white-space: nowrap;
}
.logo svg {
  flex-shrink: 0;
  color: var(--color-primary);
}

.header-nav {
  display: flex;
  gap: var(--space-6);
  font-size: var(--text-sm);
  color: var(--color-text-muted);
}
.header-nav a:hover {
  color: var(--color-text);
}

.theme-toggle {
  padding: var(--space-2);
  color: var(--color-text-muted);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
}
.theme-toggle:hover {
  color: var(--color-text);
  background: var(--color-surface-2);
}

@media (max-width: 640px) {
  .header-nav { display: none; }
  .header-inner { padding: var(--space-3) var(--space-4); }
}

/* ===========================
   HERO
   =========================== */
.hero {
  padding: clamp(var(--space-16), 10vw, var(--space-32)) var(--space-6);
  text-align: center;
}
.hero-inner {
  max-width: 720px;
  margin: 0 auto;
}

.hero-label {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-primary);
  letter-spacing: 0.03em;
  text-transform: uppercase;
  margin-bottom: var(--space-4);
}

.hero h1 {
  font-family: var(--font-display);
  font-size: var(--text-3xl);
  color: var(--color-text);
  margin-bottom: var(--space-6);
  line-height: 1.1;
}

.hero-sub {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  max-width: 560px;
  margin: 0 auto var(--space-8);
  line-height: 1.5;
}

.hero-cta {
  margin-bottom: var(--space-4);
}

.hero-footnote {
  font-size: var(--text-sm);
  color: var(--color-text-faint);
}

/* ===========================
   BUTTONS
   =========================== */
.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-6);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: 500;
  transition: all var(--transition-interactive);
  text-decoration: none;
}

.btn-primary {
  background: var(--color-primary);
  color: #fff;
}
.btn-primary:hover {
  background: var(--color-primary-hover);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}
.btn-primary:active {
  background: var(--color-primary-active);
  transform: translateY(0);
}

.btn-primary svg {
  display: inline-block;
  flex-shrink: 0;
}

.btn-large {
  padding: var(--space-4) var(--space-8);
  font-size: var(--text-base);
}

/* ===========================
   DEMO FLOW
   =========================== */
.demo-section {
  padding: 0 var(--space-6) clamp(var(--space-12), 6vw, var(--space-24));
}
.demo-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
}

.demo-flow {
  display: flex;
  align-items: flex-start;
  justify-content: center;
  gap: var(--space-4);
}

.demo-step {
  flex: 1;
  max-width: 280px;
  text-align: center;
}

.demo-arrow {
  display: flex;
  align-items: center;
  padding-top: var(--space-16);
  color: var(--color-text-faint);
}

.demo-card {
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  overflow: hidden;
  text-align: left;
  box-shadow: var(--shadow-sm);
}

.demo-card-header {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-4);
  border-bottom: 1px solid var(--color-divider);
  font-size: var(--text-xs);
  font-weight: 500;
  color: var(--color-text-muted);
}
.demo-card-header svg {
  flex-shrink: 0;
  display: inline-block;
}

.demo-card-body {
  padding: var(--space-4);
}

.demo-to {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
  margin-bottom: var(--space-1);
}
.demo-subject {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
  margin-bottom: var(--space-4);
}

.demo-attachments {
  display: flex;
  gap: var(--space-3);
}
.demo-thumb {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-2) var(--space-3);
  background: var(--color-surface-2);
  border-radius: var(--radius-sm);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}
.demo-thumb svg {
  flex-shrink: 0;
  display: inline-block;
}

.demo-processing-body {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}
.processing-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}
.processing-item.done svg {
  color: var(--color-success);
  display: inline-block;
  flex-shrink: 0;
}

.demo-collage {
  display: flex;
  gap: 2px;
  border-radius: var(--radius-sm);
  overflow: hidden;
  margin-bottom: var(--space-3);
  aspect-ratio: 2/1;
}
.collage-half {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: var(--text-xs);
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.collage-before {
  background: var(--color-surface-2);
  color: var(--color-text-faint);
}
.collage-after {
  background: var(--color-primary-light);
  color: var(--color-primary);
}

.demo-caption {
  font-size: var(--text-xs);
  color: var(--color-text-muted);
  font-style: italic;
  line-height: 1.5;
}

.demo-label {
  margin-top: var(--space-4);
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text);
}

@media (max-width: 768px) {
  .demo-flow {
    flex-direction: column;
    align-items: center;
  }
  .demo-step {
    max-width: 340px;
    width: 100%;
  }
  .demo-arrow {
    transform: rotate(90deg);
    padding-top: 0;
    padding: var(--space-2) 0;
  }
}

/* ===========================
   SECTIONS
   =========================== */
.section {
  padding: clamp(var(--space-12), 6vw, var(--space-24)) var(--space-6);
}
.section-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
}
.section-alt {
  background: var(--color-surface-2);
}

.section h2 {
  font-family: var(--font-display);
  font-size: var(--text-2xl);
  color: var(--color-text);
  margin-bottom: clamp(var(--space-8), 4vw, var(--space-12));
  text-align: center;
}

/* ===========================
   HOW IT WORKS — STEPS
   =========================== */
.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-8);
}

.step-card {
  padding: var(--space-8) var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-xl);
  text-align: center;
  box-shadow: var(--shadow-sm);
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
  background: var(--color-primary-light);
  color: var(--color-primary);
  font-family: var(--font-display);
  font-size: var(--text-xl);
  margin-bottom: var(--space-5);
}

.step-card h3 {
  font-family: var(--font-display);
  font-size: var(--text-lg);
  margin-bottom: var(--space-3);
  color: var(--color-text);
}

.step-card p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
  margin: 0 auto;
  max-width: 30ch;
}

@media (max-width: 768px) {
  .steps-grid {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }
  .step-card {
    padding: var(--space-6) var(--space-5);
  }
}

/* ===========================
   FEATURES GRID
   =========================== */
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: var(--space-6);
}

.feature {
  padding: var(--space-6);
  background: var(--color-surface);
  border: 1px solid var(--color-divider);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
}

.feature-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: var(--radius-md);
  background: var(--color-primary-light);
  color: var(--color-primary);
  margin-bottom: var(--space-4);
}

.feature h3 {
  font-family: var(--font-body);
  font-weight: 600;
  font-size: var(--text-base);
  margin-bottom: var(--space-2);
  color: var(--color-text);
}

.feature p {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  line-height: 1.6;
}

@media (max-width: 768px) {
  .features-grid {
    grid-template-columns: 1fr;
    gap: var(--space-4);
  }
}

/* ===========================
   SECURITY
   =========================== */
.security-layout {
  display: grid;
  grid-template-columns: 1fr 300px;
  gap: var(--space-12);
  align-items: center;
}

.security-text h2 {
  text-align: left;
}

.security-intro {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  margin-bottom: var(--space-8);
  max-width: 50ch;
}

.security-list {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.security-list li {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  font-size: var(--text-sm);
  color: var(--color-text);
  max-width: none;
}
.security-list li svg {
  flex-shrink: 0;
  color: var(--color-success);
  margin-top: 2px;
  display: inline-block;
}

.security-visual {
  display: flex;
  align-items: center;
  justify-content: center;
}

.shield-graphic {
  color: var(--color-primary);
}

@media (max-width: 768px) {
  .security-layout {
    grid-template-columns: 1fr;
    gap: var(--space-8);
  }
  .security-visual {
    order: -1;
  }
  .security-text h2 {
    text-align: center;
  }
  .security-intro {
    text-align: center;
    margin-left: auto;
    margin-right: auto;
  }
}

/* ===========================
   CTA
   =========================== */
.cta-section {
  text-align: center;
  background: var(--color-surface-2);
  border-top: 1px solid var(--color-divider);
}
.cta-inner {
  max-width: 600px;
  margin: 0 auto;
}
.cta-section h2 {
  margin-bottom: var(--space-4);
}
.cta-section > .section-inner > p,
.cta-inner > p:first-of-type {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  margin-bottom: var(--space-8);
}
.cta-address {
  margin-top: var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-text-faint);
  font-family: monospace;
}

/* ===========================
   FOOTER
   =========================== */
.footer {
  padding: var(--space-6);
  border-top: 1px solid var(--color-divider);
}
.footer-inner {
  max-width: var(--content-wide);
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}
.footer-left {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-size: var(--text-xs);
  color: var(--color-text-muted);
}
.footer-brand {
  font-weight: 600;
  color: var(--color-text);
}
.footer-sep {
  color: var(--color-text-faint);
}
.footer-right {
  font-size: var(--text-xs);
  color: var(--color-text-faint);
}
.footer-right a:hover {
  color: var(--color-text-muted);
}

@media (max-width: 640px) {
  .footer-inner {
    flex-direction: column;
    text-align: center;
  }
}

/* ===========================
   SCROLL REVEAL ANIMATION
   =========================== */
.reveal {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.5s cubic-bezier(0.16, 1, 0.3, 1),
              transform 0.5s cubic-bezier(0.16, 1, 0.3, 1);
}
.reveal.revealed {
  opacity: 1;
  transform: translateY(0);
}

/* Stagger children */
.step-card:nth-child(2) { transition-delay: 0.08s; }
.step-card:nth-child(3) { transition-delay: 0.16s; }

.feature:nth-child(2) { transition-delay: 0.06s; }
.feature:nth-child(3) { transition-delay: 0.12s; }
.feature:nth-child(4) { transition-delay: 0.04s; }
.feature:nth-child(5) { transition-delay: 0.10s; }
.feature:nth-child(6) { transition-delay: 0.16s; }

.security-list li:nth-child(2) { transition-delay: 0.06s; }
.security-list li:nth-child(3) { transition-delay: 0.12s; }
.security-list li:nth-child(4) { transition-delay: 0.18s; }
.security-list li:nth-child(5) { transition-delay: 0.24s; }
.security-list li:nth-child(6) { transition-delay: 0.30s; }

.demo-step:nth-child(1) { transition-delay: 0s; }
.demo-step:nth-child(3) { transition-delay: 0.1s; }
.demo-step:nth-child(5) { transition-delay: 0.2s; }