/* ===================================
   Original CSS - skyechan Portfolio
   Material Design Inspired + #102a28
   =================================== */

/* --- Reset & Variables --- */
*,
*::before,
*::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

.skip-nav {
  position: absolute;
  top: -100%;
  left: 16px;
  background: var(--color-accent);
  color: var(--color-base);
  padding: 12px 24px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 0.875rem;
  z-index: 9999;
  transition: top 0.2s ease;
}

.skip-nav:focus {
  top: 16px;
}

:root {
  --color-base:      #102a28;
  --color-surface:   #163533;
  --color-card:      #1a3d3a;
  --color-elevated:  #1e4643;
  --color-text:      #c4d4d2;
  --color-text-sub:  #7a9a96;
  --color-white:     #e8f0ef;
  --color-accent:    #4db6ac;
  --color-accent2:   #80cbc4;
  --color-border:    #244744;
  --color-ripple:    rgba(77, 182, 172, 0.15);

  --shadow-1: 0 1px 3px rgba(0,0,0,0.24), 0 1px 2px rgba(0,0,0,0.36);
  --shadow-2: 0 3px 6px rgba(0,0,0,0.28), 0 3px 6px rgba(0,0,0,0.33);
  --shadow-3: 0 10px 20px rgba(0,0,0,0.30), 0 6px 6px rgba(0,0,0,0.30);
  --shadow-4: 0 14px 28px rgba(0,0,0,0.35), 0 10px 10px rgba(0,0,0,0.32);

  --radius: 12px;
  --radius-sm: 8px;
  --font: 'Noto Sans JP', 'Roboto', -apple-system, BlinkMacSystemFont, sans-serif;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);

  --sidebar-width: 72px;
  --sidebar-expanded: 220px;
}

html {
  scroll-behavior: smooth;
  font-size: 16px;
}

body {
  font-family: var(--font);
  font-weight: 400;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-base);
  -webkit-font-smoothing: antialiased;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

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

/* --- Fade-in Animation --- */
.fade-in {
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s cubic-bezier(0.4, 0, 0.2, 1),
              transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.fade-in.is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ===================================
   Sidebar
   =================================== */
.sidebar {
  position: fixed;
  top: 0;
  left: 0;
  width: var(--sidebar-width);
  height: 100vh;
  background: var(--color-surface);
  border-right: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  align-items: center;
  padding: 20px 0;
  z-index: 100;
  transition: width var(--transition), box-shadow var(--transition);
}

.sidebar:hover {
  width: var(--sidebar-expanded);
  box-shadow: var(--shadow-3);
}

.sidebar__top {
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 100%;
}

.sidebar__avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  overflow: hidden;
  background: var(--color-card);
  border: 2px solid var(--color-accent);
  margin-bottom: 24px;
  flex-shrink: 0;
  transition: transform var(--transition);
}

.sidebar:hover .sidebar__avatar {
  transform: scale(1.1);
}

.sidebar__logo {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.sidebar__nav {
  display: flex;
  flex-direction: column;
  gap: 4px;
  width: 100%;
  padding: 0 10px;
}

.sidebar__link {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  color: var(--color-text-sub);
  font-size: 0.85rem;
  font-weight: 500;
  transition: background var(--transition), color var(--transition);
  white-space: nowrap;
  overflow: hidden;
  position: relative;
}

.sidebar__link:hover {
  background: var(--color-ripple);
  color: var(--color-white);
}

.sidebar__link.active {
  background: rgba(77, 182, 172, 0.12);
  color: var(--color-accent);
}

.sidebar__link.active::before {
  content: '';
  position: absolute;
  left: -10px;
  top: 50%;
  transform: translateY(-50%);
  width: 3px;
  height: 20px;
  background: var(--color-accent);
  border-radius: 0 3px 3px 0;
}

.sidebar__link .material-icons-round {
  font-size: 22px;
  flex-shrink: 0;
}

.sidebar__label {
  opacity: 0;
  transition: opacity var(--transition);
}

.sidebar:hover .sidebar__label {
  opacity: 1;
}

.sidebar__bottom {
  display: flex;
  flex-direction: column;
  gap: 4px;
  width: 100%;
  padding: 0 10px;
}

.sidebar__bottom .sidebar__link {
  justify-content: center;
}

.sidebar:hover .sidebar__bottom .sidebar__link {
  justify-content: flex-start;
}

/* ===================================
   Mobile Header
   =================================== */
.mobile-header {
  display: none;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 56px;
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  align-items: center;
  padding: 0 16px;
  z-index: 110;
}

.mobile-header__hamburger {
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.mobile-header__hamburger span {
  display: block;
  width: 20px;
  height: 1.5px;
  background: var(--color-text);
  transition: var(--transition);
  transform-origin: center;
}

.mobile-header__hamburger.is-open span:nth-child(1) {
  transform: translateY(6.5px) rotate(45deg);
}

.mobile-header__hamburger.is-open span:nth-child(2) {
  opacity: 0;
}

.mobile-header__hamburger.is-open span:nth-child(3) {
  transform: translateY(-6.5px) rotate(-45deg);
}

.mobile-header__title {
  font-size: 0.95rem;
  font-weight: 500;
  color: var(--color-white);
  margin-left: 12px;
}

/* ===================================
   Main Content
   =================================== */
.main {
  margin-left: var(--sidebar-width);
  flex: 1;
  min-height: 100vh;
}

.section {
  min-height: 100vh;
  padding: 80px 60px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.section__header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 40px;
}

.section__icon {
  font-size: 28px;
  color: var(--color-accent);
}

.section__title {
  font-size: 1.8rem;
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: 0.05em;
}

/* ===================================
   Hero Section
   =================================== */
.hero {
  position: relative;
  overflow: hidden;
}

.hero__content {
  position: relative;
  z-index: 1;
}

.hero__greeting {
  font-size: 1rem;
  color: var(--color-accent);
  font-weight: 500;
  letter-spacing: 0.1em;
  margin-bottom: 12px;
}

.hero__name {
  font-size: clamp(3rem, 8vw, 5.5rem);
  font-weight: 700;
  color: var(--color-white);
  letter-spacing: 0.04em;
  line-height: 1.1;
  margin-bottom: 8px;
}

.hero__role {
  font-size: 1.1rem;
  font-weight: 300;
  letter-spacing: 0.12em;
  color: var(--color-accent2);
  margin-bottom: 20px;
}

.hero__desc {
  font-size: 0.95rem;
  color: var(--color-text-sub);
  margin-bottom: 36px;
}

.hero__actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}

/* Material Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 12px 28px;
  border-radius: var(--radius);
  font-size: 0.875rem;
  font-weight: 500;
  letter-spacing: 0.03em;
  transition: background var(--transition), box-shadow var(--transition), transform 0.15s ease;
  cursor: pointer;
  border: none;
}

.btn:active {
  transform: scale(0.97);
}

.btn--primary {
  background: var(--color-accent);
  color: var(--color-base);
}

.btn--primary:hover {
  background: var(--color-accent2);
  box-shadow: var(--shadow-2);
}

.btn--outline {
  background: transparent;
  color: var(--color-accent);
  border: 1.5px solid var(--color-accent);
}

.btn--outline:hover {
  background: rgba(77, 182, 172, 0.08);
}

/* Hero Decoration */
.hero__decoration {
  position: absolute;
  top: 0;
  right: 0;
  width: 50%;
  height: 100%;
  pointer-events: none;
}

.hero__circle {
  position: absolute;
  border-radius: 50%;
  border: 1px solid var(--color-border);
}

.hero__circle--1 {
  width: 400px;
  height: 400px;
  top: 15%;
  right: 10%;
  background: radial-gradient(circle, rgba(77,182,172,0.04), transparent 70%);
  animation: float 8s ease-in-out infinite;
  display: flex;
  align-items: center;
  justify-content: center;
}

.hero__logo {
  width: 60%;
  height: 60%;
  object-fit: contain;
  opacity: 0.85;
  filter: drop-shadow(0 0 20px rgba(77, 182, 172, 0.15));
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%      { transform: translateY(-20px); }
}

/* ===================================
   About Section
   =================================== */
.about {
  background: var(--color-surface);
}

.about__content {
  max-width: 720px;
}

.about__bio p {
  font-size: 0.95rem;
  line-height: 2;
  margin-bottom: 20px;
  color: var(--color-text);
}

.about__skills {
  margin-top: 36px;
}

.about__skills-title {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--color-accent);
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}

.about__skills-title .material-icons-round {
  font-size: 20px;
}

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

.skill__chip {
  background: var(--color-card);
  border: 1px solid var(--color-border);
  border-radius: 100px;
  padding: 8px 20px;
  font-size: 0.8rem;
  font-weight: 400;
  color: var(--color-text);
  transition: border-color var(--transition), background var(--transition), color var(--transition);
}

.skill__chip:hover {
  border-color: var(--color-accent);
  background: rgba(77, 182, 172, 0.08);
  color: var(--color-white);
}

/* ===================================
   Works Section
   =================================== */
.works__grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

/* Material Card */
.material-card {
  background: var(--color-card);
  border-radius: var(--radius);
  overflow: hidden;
  transition: box-shadow var(--transition), transform var(--transition);
  border: 1px solid var(--color-border);
}

.material-card:hover {
  box-shadow: var(--shadow-2);
  transform: translateY(-2px);
}

.works__card-header {
  height: 120px;
  background: linear-gradient(135deg, var(--color-elevated), var(--color-surface));
  display: flex;
  align-items: center;
  justify-content: center;
}

.works__card-icon {
  font-size: 40px;
  color: var(--color-accent);
  opacity: 0.7;
}

.works__card-body {
  padding: 20px;
}

.works__card-title {
  font-size: 1rem;
  font-weight: 500;
  color: var(--color-white);
  margin-bottom: 6px;
}

.works__card-desc {
  font-size: 0.8rem;
  color: var(--color-text-sub);
  line-height: 1.6;
  margin-bottom: 14px;
}

.works__card-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.tag {
  font-size: 0.7rem;
  padding: 3px 10px;
  border-radius: 100px;
  background: rgba(77, 182, 172, 0.1);
  color: var(--color-accent);
  font-weight: 500;
}

/* ===================================
   Responsive
   =================================== */
@media (max-width: 900px) {
  .sidebar {
    width: 0;
    transform: translateX(-100%);
    overflow: hidden;
    visibility: hidden;
  }

  .sidebar.is-open {
    width: var(--sidebar-expanded);
    transform: translateX(0);
    box-shadow: var(--shadow-4);
    visibility: visible;
    overflow: visible;
    z-index: 120;
  }

  .sidebar:hover {
    width: var(--sidebar-expanded);
  }

  .sidebar__label {
    opacity: 1;
  }

  .sidebar__bottom .sidebar__link {
    justify-content: flex-start;
  }

  .mobile-header {
    display: flex;
  }

  .main {
    margin-left: 0;
    padding-top: 56px;
  }

  .section {
    min-height: calc(100vh - 56px);
    padding: 60px 24px;
  }

  .hero__circle--1 {
    width: 220px;
    height: 220px;
  }

  .hero__logo {
    width: 55%;
    height: 55%;
  }

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

  .footer {
    padding: 24px;
  }
}

@media (max-width: 480px) {
  .hero {
    padding: 40px 16px;
  }

  .hero__name {
    font-size: 2.2rem;
  }

  .hero__role {
    font-size: 0.85rem;
    letter-spacing: 0.08em;
  }

  .hero__desc {
    font-size: 0.85rem;
  }

  .hero__actions {
    flex-direction: column;
    gap: 12px;
  }

  .btn {
    justify-content: center;
    width: 100%;
    padding: 14px 20px;
  }

  .hero__circle--1 {
    width: 160px;
    height: 160px;
    top: 10%;
    right: 5%;
    opacity: 0.5;
  }

  .hero__logo {
    width: 50%;
    height: 50%;
  }

  .section {
    padding: 40px 16px;
  }

  .section__title {
    font-size: 1.4rem;
  }

  .works__card-header {
    height: 90px;
  }

  .works__card-body {
    padding: 16px;
  }

  .about__bio p {
    font-size: 0.85rem;
  }

  .footer {
    padding: 16px;
  }
}

/* ===================================
   Footer
   =================================== */
.footer {
  background: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding: 24px 60px;
  text-align: center;
}

.footer__copy {
  font-size: 0.8rem;
  color: var(--color-text-sub);
  margin-bottom: 4px;
}

.footer__built {
  font-size: 0.7rem;
  color: var(--color-border);
}