/* ============================================================
   swissmodern — style.css
   Design system: sign-tokyo aesthetic, opacity-only animations,
   100% CSS custom property layout, no magic numbers.
   ============================================================ */


/* ============================================================
   SECTION 1: :root — all design tokens
   ============================================================ */

:root {
  /* Color */
  --color-bg:               #111111;
  --color-text-primary:     #ffffff;
  --color-text-secondary:   rgba(255, 255, 255, 0.85);
  --color-accent:           #e8e8e8;
  --color-accent-hover:     rgba(232, 232, 232, 0.85);
  --color-overlay-bg:       rgba(17, 17, 17, 0.55);
  --color-page-transition:  #111111;

  /* Typography */
  --font-primary:             'DM Sans', sans-serif;
  --font-size-nav-items:      clamp(0.9rem, 1.4vw, 1.05rem);
  --font-size-section-title:  clamp(1.4rem, 2.5vw, 2rem);
  --font-size-body:           clamp(0.9rem, 1.4vw, 1.05rem);
  --font-size-utility:        11px;
  --font-weight-regular:      400;
  --font-weight-light:        300;
  --line-height-body:         1.8;
  --letter-spacing-utility:   0.08em;

  /* Layout */
  --nav-height:           64px;
  --inset-x:              8vw;
  --inset-y:              8vh;

  /* Homepage sections */
  --section-height:   100vh;
  --scrim-start:      45%;
  --scrim-opacity:    0.72;

  /* Subpage hero */
  --subpage-hero-height: 60vh;

  /* Hamburger panel */
  --panel-width:      280px;
  --panel-padding-x:  1.5rem;
  --panel-padding-y:  1.75rem;
  --panel-nav-gap:    1.5rem;

  /* Utility cluster */
  --utility-gap:           1.5rem;
  --utility-opacity:       0.55;
  --utility-opacity-hover: 0.85;

  /* Animations — OPACITY ONLY, no positional movement */
  --fade-duration:  300ms;
  --fade-page:      400ms;
  --fade-reveal:    600ms;
  --fade-easing:    linear;
}


/* ============================================================
   SECTION 2: Font + Reset + Base
   ============================================================ */

@font-face {
  font-family: 'DM Sans';
  src: url('/assets/fonts/DM_Sans/DMSans-VariableFont_opsz,wght.ttf') format('truetype');
  font-weight: 100 900;
  font-style: normal;
  font-display: swap;
}

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

html {
  color-scheme: dark;
}

body {
  font-family: var(--font-primary);
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-light);
  line-height: var(--line-height-body);
  color: var(--color-text-primary);
  background-color: var(--color-bg);
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

img {
  display: block;
  max-width: 100%;
}

a {
  color: inherit;
  text-decoration: none;
}

button {
  background: none;
  border: none;
  cursor: pointer;
  color: inherit;
  font-family: inherit;
  padding: 0;
}


/* ============================================================
   SECTION 3: Page Transition Overlay
   ============================================================ */

.page-transition {
  position: fixed;
  inset: 0;
  background-color: var(--color-page-transition);
  z-index: 9999;
  pointer-events: none;
  opacity: 0;
  transition: opacity var(--fade-page) var(--fade-easing);
}

.page-transition.is-visible {
  opacity: 1;
  pointer-events: all;
}

body.is-loading .page-transition {
  opacity: 1;
}


/* ============================================================
   SECTION 4: Header
   ============================================================ */

.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--inset-x);
  z-index: 100;
}

.site-logo {
  font-size: calc(var(--font-size-body) * 1.25);
  font-weight: var(--font-weight-regular);
  letter-spacing: 0.04em;
  text-transform: lowercase;
  transition: opacity var(--fade-duration) var(--fade-easing);
}

.site-logo:hover {
  opacity: 0.7;
}

.header-utility {
  display: flex;
  align-items: center;
  gap: var(--utility-gap);
}

.util-item {
  font-size: var(--font-size-utility);
  letter-spacing: var(--letter-spacing-utility);
  color: var(--color-accent);
  opacity: var(--utility-opacity);
  transition: opacity var(--fade-duration) var(--fade-easing);
  display: flex;
  align-items: center;
}

.util-item:hover {
  opacity: var(--utility-opacity-hover);
}

.util-item svg {
  width: 14px;
  height: 14px;
  fill: currentColor;
}

.lang-toggle {
  font-size: var(--font-size-utility);
  letter-spacing: var(--letter-spacing-utility);
  color: var(--color-accent);
  opacity: var(--utility-opacity);
  text-transform: lowercase;
  transition: opacity var(--fade-duration) var(--fade-easing);
}

.lang-toggle:hover {
  opacity: var(--utility-opacity-hover);
}

.menu-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 1;
  padding: 8px;
  transition: opacity var(--fade-duration) var(--fade-easing);
}

.menu-toggle:hover {
  opacity: 0.7;
}

.menu-toggle svg {
  width: 20px;
  height: 14px;
}

.menu-toggle .icon-close {
  display: none;
}

.menu-toggle .icon-open {
  display: block;
}

.site-header.menu-is-open .menu-toggle .icon-close {
  display: block;
}

.site-header.menu-is-open .menu-toggle .icon-open {
  display: none;
}


/* ============================================================
   SECTION 5: Hamburger Panel
   ============================================================ */

.menu-panel {
  position: fixed;
  top: var(--nav-height);
  right: 0;
  width: var(--panel-width);
  background-color: var(--color-overlay-bg);
  padding: var(--panel-padding-y) var(--panel-padding-x);
  z-index: 99;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--fade-duration) var(--fade-easing);
}

.menu-panel.is-open {
  opacity: 1;
  pointer-events: all;
}

.menu-panel {
  display: flex;
  flex-direction: column;
  gap: var(--panel-nav-gap);
}

.menu-panel a {
  font-size: var(--font-size-nav-items);
  font-weight: var(--font-weight-light);
  text-transform: lowercase;
  line-height: 1;
  transition: opacity var(--fade-duration) var(--fade-easing);
}

.menu-panel a:hover {
  opacity: 0.6;
}


/* ============================================================
   SECTION 6: Homepage sections (hero + scrim + text reveal)
   ============================================================ */

.hero-section {
  position: relative;
  width: 100%;
  height: var(--section-height);
  overflow: hidden;
  /* Fallback background if image missing */
  background-color: #1a1a1a;
}

.hero-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
}

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center;
}

.hero-scrim {
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(
    to bottom,
    transparent var(--scrim-start),
    rgba(0, 0, 0, var(--scrim-opacity)) 100%
  );
}

.hero-content {
  position: absolute;
  bottom: var(--inset-y);
  left: var(--inset-x);
  right: var(--inset-x);
  z-index: 2;
  opacity: 0;
  transition: opacity var(--fade-reveal) ease-out;
}

.hero-content.is-visible {
  opacity: 1;
}

.section-title {
  font-size: var(--font-size-section-title);
  font-weight: var(--font-weight-regular);
  text-transform: lowercase;
  letter-spacing: 0.02em;
  margin-bottom: 0.75rem;
  white-space: nowrap;
}

.section-body {
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-light);
  color: var(--color-text-secondary);
}

.site-footer {
  height: 40px;
  display: flex;
  align-items: center;
  padding: 0 var(--inset-x);
}

.copyright {
  font-size: var(--font-size-utility);
  letter-spacing: var(--letter-spacing-utility);
  color: var(--color-accent);
  opacity: var(--utility-opacity);
  text-transform: lowercase;
}


/* ============================================================
   SECTION 7: Subpage layout
   ============================================================ */

.subpage-hero {
  position: relative;
  width: 100%;
  height: var(--subpage-hero-height);
  overflow: hidden;
  background-color: #1a1a1a;
}

.subpage-hero .hero-content {
  opacity: 1;
}

/* Portrait hero section — height determined by image, not viewport */
.hero-section--portrait {
  height: auto;
}

.hero-section--portrait .hero-bg {
  position: relative;
  width: 100%;
}

.hero-section--portrait .hero-bg img {
  width: 100%;
  height: auto;
  object-fit: initial;
  object-position: initial;
}

.subpage-content {
  background-color: var(--color-bg);
  padding: 5rem var(--inset-x);
}

.subpage-content p,
.subpage-content .content-text {
  font-size: var(--font-size-body);
  font-weight: var(--font-weight-light);
  color: var(--color-text-secondary);
  line-height: var(--line-height-body);
  margin-bottom: 1.5rem;
}

.contact-icons {
  display: flex;
  gap: 1.5rem;
  margin-top: 2.5rem;
}

.contact-icons a {
  color: var(--color-accent);
  opacity: var(--utility-opacity);
  transition: opacity var(--fade-duration) var(--fade-easing);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: var(--font-size-utility);
  letter-spacing: var(--letter-spacing-utility);
}

.contact-icons a:hover {
  opacity: var(--utility-opacity-hover);
}

.contact-icons svg {
  width: 16px;
  height: 16px;
  fill: currentColor;
}


/* ============================================================
   SECTION 8: Responsive breakpoints
   ============================================================ */

@media (max-width: 768px) {
  :root {
    --inset-x: 6vw;
    --panel-width: 240px;
  }
}

@media (max-width: 480px) {
  :root {
    --inset-x: 5vw;
    --inset-y: 5vh;
    --panel-width: 100vw;
    --utility-gap: 1rem;
  }

  .section-body {
    max-width: 90vw;
  }
}