/* ============================================
   Ivan Kisin — Portfolio
   Minimal single-column layout inspired by lolajiang.com
   ============================================ */

:root {
  --color-black: #111;
  --color-white: #fff;
  --color-gray-light: #f5f5f5;
  --color-gray-mid: #666;
  --color-gray-border: #e0e0e0;
  --font-heading: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-nav: 'Julius Sans One', sans-serif;
  --font-body: 'Quattrocento', Georgia, 'Times New Roman', serif;
  --nav-height: 64px;
  --content-width: 1080px;
  --transition: 0.3s ease;
}

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

html {
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  color: var(--color-black);
  background: var(--color-white);
  line-height: 1.6;
  font-size: 16px;
}

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

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

h2, h3, h4, h5, h6,
.btn, .project-link,
.resume-skill-tag, .resume-meta, .case-study-back, .case-study-next {
  font-family: var(--font-heading);
}

h1 {
  font-family: var(--font-body);
}

.nav-logo, .nav-link {
  font-family: var(--font-nav);
}

/* ---- Navigation ---- */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--nav-height);
  background: transparent;
  z-index: 1000;
  transition: background var(--transition);
}

.nav.scrolled {
  background: rgba(255, 255, 255, 0.97);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.nav-inner {
  max-width: 100%;
  margin: 0 auto;
  padding: 0 48px;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-logo {
  display: flex;
  align-items: center;
}

.nav-logo-img {
  height: 24px;
  width: auto;
}

.nav-links {
  display: flex;
  gap: 36px;
}

.nav-link {
  font-size: 12px;
  font-weight: 400;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  color: var(--color-gray-mid);
  transition: color var(--transition);
  position: relative;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 1px;
  background: var(--color-black);
  transition: width var(--transition);
}

.nav-link:hover,
.nav-link.active {
  color: var(--color-black);
}

.nav-link.active::after {
  width: 100%;
}

/* Mobile toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  width: 24px;
  height: 18px;
  position: relative;
  z-index: 1001;
}

.nav-toggle span {
  display: block;
  width: 100%;
  height: 2px;
  background: var(--color-black);
  position: absolute;
  left: 0;
  transition: all var(--transition);
}

.nav-toggle span:first-child { top: 3px; }
.nav-toggle span:last-child { bottom: 3px; }

.nav-toggle.open span:first-child {
  top: 50%;
  transform: translateY(-50%) rotate(45deg);
}

.nav-toggle.open span:last-child {
  bottom: 50%;
  transform: translateY(50%) rotate(-45deg);
}

/* ---- Fixed Social Icons (bottom right) ---- */
.social-fixed {
  position: fixed;
  bottom: 32px;
  right: 40px;
  display: flex;
  gap: 16px;
  z-index: 999;
}

.social-fixed-icon {
  color: var(--color-gray-mid);
  transition: color var(--transition);
}

.social-fixed-icon:hover {
  color: var(--color-black);
}

/* ---- Hero (full viewport with background) ---- */
.hero {
  position: relative;
  width: 100%;
  height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background-image: url('https://images.unsplash.com/photo-1631929418913-922fec1b5f5d?w=1920&q=80&auto=format');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}

.hero::before {
  content: '';
  position: absolute;
  inset: 0;
  background: rgba(255, 255, 255, 0.15);
}

.hero-content {
  position: relative;
  z-index: 1;
  text-align: left;
  padding-left: 24px;
  border-left: 1px solid var(--color-black);
  max-width: 420px;
}

.hero h1 {
  font-size: clamp(32px, 4vw, 44px);
  font-weight: 400;
  letter-spacing: -0.02em;
  line-height: 1.1;
  margin-bottom: 16px;
  color: var(--color-black);
}

.hero-tagline {
  font-size: 15px;
  color: #444;
  line-height: 1.7;
}

.hero-scroll {
  position: absolute;
  bottom: 48px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 1;
  color: var(--color-black);
  opacity: 0.6;
  transition: opacity var(--transition);
  animation: gentleBounce 2.5s ease-in-out infinite;
}

.hero-scroll:hover {
  opacity: 1;
}

@keyframes gentleBounce {
  0%, 100% { transform: translateX(-50%) translateY(0); }
  50% { transform: translateX(-50%) translateY(8px); }
}

/* ---- Projects (two-column: text left, image right) ---- */
.projects {
  display: flex;
  flex-direction: column;
}

.project {
  display: grid;
  grid-template-columns: 2fr 3fr;
  gap: 60px;
  align-items: center;
  padding: 80px 48px;
  max-width: 1200px;
  margin: 0 auto;
  width: 100%;
}

.project-section {
  padding: 0;
}

.project-section:nth-child(even) {
  background: var(--color-gray-light);
}

.project-section:nth-child(odd) {
  background: var(--color-white);
}

.project--reverse {
  grid-template-columns: 3fr 2fr;
}

.project--reverse .project-image-link {
  order: -1;
}

.project-text {
  display: flex;
  flex-direction: column;
  justify-content: center;
}

.project-text-inner {
  padding-left: 24px;
  border-left: 1px solid var(--color-black);
  margin-bottom: 28px;
}

.project-text h2 {
  font-family: var(--font-body);
  font-size: clamp(28px, 3.5vw, 38px);
  font-weight: 400;
  letter-spacing: -0.01em;
  line-height: 1.2;
  margin-bottom: 20px;
}

.project-desc {
  font-size: 14px;
  color: var(--color-gray-mid);
  line-height: 1.75;
}

.project-btn {
  display: inline-block;
  padding: 10px 24px;
  margin-left: 24px;
  font-family: var(--font-body);
  font-size: 13px;
  color: var(--color-black);
  border: 1px solid var(--color-black);
  border-radius: 2px;
  transition: all var(--transition);
  align-self: flex-start;
}

.project-btn:hover {
  background: var(--color-black);
  color: var(--color-white);
}

.project-image-link {
  display: block;
  overflow: hidden;
  border-radius: 8px;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08), 0 1px 6px rgba(0, 0, 0, 0.04);
}

.project-image {
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  object-position: center;
  transition: transform 0.5s ease;
}

.project-image-link:hover .project-image {
  transform: scale(1.02);
}

/* ---- Coaching Page ---- */
.page-header {
  padding: 160px 48px 60px;
  max-width: var(--content-width);
  margin: 0 auto;
}

.page-header h1 {
  font-size: clamp(36px, 5vw, 52px);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1.1;
  margin-bottom: 16px;
}

.page-header p {
  font-size: clamp(16px, 2vw, 18px);
  color: var(--color-gray-mid);
  max-width: 580px;
  line-height: 1.65;
}

.coaching-content {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: 0 48px 100px;
}

.coaching-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 32px;
  margin-bottom: 60px;
}

.coaching-card {
  padding: 36px;
  border: 1px solid var(--color-gray-border);
  border-radius: 4px;
  transition: border-color var(--transition);
}

.coaching-card:hover {
  border-color: var(--color-black);
}

.coaching-card h3 {
  font-size: 20px;
  font-weight: 700;
  margin-bottom: 12px;
  letter-spacing: -0.01em;
}

.coaching-card p {
  font-size: 15px;
  color: var(--color-gray-mid);
  line-height: 1.7;
}

.btn {
  display: inline-block;
  padding: 14px 36px;
  background: var(--color-black);
  color: var(--color-white);
  font-size: 14px;
  font-weight: 600;
  border: none;
  border-radius: 2px;
  cursor: pointer;
  transition: opacity var(--transition);
  text-align: center;
}

.btn:hover {
  opacity: 0.8;
}

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

.btn--outline:hover {
  background: var(--color-black);
  color: var(--color-white);
}

/* ---- Resume Page ---- */
.resume-content {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 48px 100px;
}

.resume-download {
  margin-bottom: 60px;
}

.resume-section {
  margin-bottom: 56px;
}

.resume-section h2 {
  font-size: 13px;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: var(--color-gray-mid);
  margin-bottom: 28px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--color-gray-border);
}

.resume-item {
  margin-bottom: 32px;
}

.resume-item h3 {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
  margin-bottom: 4px;
}

.resume-item .resume-meta {
  font-size: 14px;
  color: var(--color-gray-mid);
  margin-bottom: 10px;
}

.resume-item p {
  font-size: 15px;
  color: var(--color-gray-mid);
  line-height: 1.7;
}

.resume-skills {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.resume-skill-tag {
  font-size: 13px;
  padding: 6px 14px;
  border: 1px solid var(--color-gray-border);
  border-radius: 100px;
  color: var(--color-black);
  font-weight: 500;
}

/* ---- Case Study ---- */
.case-study {
  max-width: 720px;
  margin: 0 auto;
  padding: 0 48px 100px;
}

.case-study-hero-img {
  width: calc(100% + 96px);
  margin-left: -48px;
  max-width: none;
  aspect-ratio: 16 / 7;
  object-fit: cover;
  margin-bottom: 60px;
}

.case-study h2 {
  font-size: clamp(22px, 3vw, 28px);
  font-weight: 700;
  letter-spacing: -0.02em;
  margin-bottom: 14px;
  margin-top: 44px;
}

.case-study p {
  font-size: 15px;
  color: var(--color-gray-mid);
  line-height: 1.8;
  margin-bottom: 18px;
}

.case-study-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: 56px;
}

.case-study-back,
.case-study-next {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-size: 14px;
  font-weight: 500;
  color: var(--color-gray-mid);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color var(--transition);
}

.case-study-back:hover,
.case-study-next:hover {
  color: var(--color-black);
}

/* ---- Password Modal ---- */
.password-modal {
  display: none;
  position: fixed;
  inset: 0;
  z-index: 2000;
  align-items: center;
  justify-content: center;
}

.password-modal.open {
  display: flex;
}

.password-modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.5);
}

.password-modal-content {
  position: relative;
  background: var(--color-white);
  padding: 48px;
  border-radius: 8px;
  width: 100%;
  max-width: 400px;
  margin: 0 24px;
  text-align: center;
}

.password-modal-close {
  position: absolute;
  top: 16px;
  right: 20px;
  background: none;
  border: none;
  font-size: 24px;
  cursor: pointer;
  color: var(--color-gray-mid);
  transition: color var(--transition);
}

.password-modal-close:hover {
  color: var(--color-black);
}

.password-modal-content h3 {
  font-size: 22px;
  font-weight: 700;
  margin-bottom: 8px;
}

.password-modal-content p {
  font-size: 14px;
  color: var(--color-gray-mid);
  margin-bottom: 24px;
}

.password-modal-input {
  width: 100%;
  padding: 12px 16px;
  font-family: var(--font-body);
  font-size: 15px;
  border: 1px solid var(--color-gray-border);
  border-radius: 4px;
  outline: none;
  transition: border-color var(--transition);
  margin-bottom: 8px;
}

.password-modal-input:focus {
  border-color: var(--color-black);
}

.password-modal-error {
  color: #c0392b !important;
  font-size: 13px !important;
  margin-bottom: 16px !important;
  display: none;
}

.password-modal-error.visible {
  display: block;
}

.password-modal-content .btn {
  width: 100%;
}

/* ---- Password Gate Button Reset ---- */
button.project-btn {
  cursor: pointer;
  background: none;
  font-family: var(--font-body);
}

/* ---- Footer ---- */
.footer {
  padding: 40px 48px;
  text-align: center;
  font-size: 13px;
  color: var(--color-gray-mid);
  border-top: 1px solid var(--color-gray-border);
}

/* ---- Mobile ---- */
@media (max-width: 768px) {
  .nav-inner {
    padding: 0 24px;
  }

  .nav-toggle {
    display: block;
  }

  .nav-links {
    position: fixed;
    top: 0;
    right: 0;
    width: 100%;
    height: 100vh;
    background: var(--color-white);
    flex-direction: column;
    align-items: center;
    justify-content: center;
    gap: 28px;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition);
  }

  .nav-links.open {
    opacity: 1;
    pointer-events: auto;
  }

  .nav-link {
    font-size: 16px;
  }

  .hero-content {
    max-width: 320px;
    padding-left: 20px;
  }

  .project {
    grid-template-columns: 1fr;
    padding: 48px 24px;
    gap: 28px;
  }

  .project--reverse {
    grid-template-columns: 1fr;
  }

  .project--reverse .project-image-link {
    order: unset;
  }

  .page-header {
    padding: 130px 24px 40px;
  }

  .coaching-content,
  .resume-content,
  .case-study {
    padding-left: 24px;
    padding-right: 24px;
  }

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

  .case-study-hero-img {
    width: calc(100% + 48px);
    margin-left: -24px;
  }

  .social-fixed {
    bottom: 20px;
    right: 20px;
  }
}