/* ==========================================================================
   Alexandru-Tudor Chiujdea — Portfolio
   Design Tokens & Theme System
   ========================================================================== */

:root {
  --bg: #ffffff;
  --bg-alpha: rgba(255, 255, 255, 0.85);
  --text-main: #171717;
  --text-secondary: #737373;
  --border: #e5e5e5;
  --hover-bg: #f5f5f5;
  --email-btn-bg: #6F00C5;
  --email-btn-text: #ffffff;
  --focus-ring: #2563eb;
  --font-sans: -apple-system, BlinkMacSystemFont, "Inter", "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

[data-theme="dark"] {
  --bg: #0a0a0a;
  --bg-alpha: rgba(10, 10, 10, 0.85);
  --text-main: #ededed;
  --text-secondary: #a3a3a3;
  --border: #262626;
  --hover-bg: #171717;
  --email-btn-bg: #00E5FF;
  --email-btn-text: #0a0a0a;
  --focus-ring: #00E5FF;
}

/* ==========================================================================
   Reset & Base
   ========================================================================== */

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

:focus-visible {
  outline: 2px solid var(--focus-ring);
  outline-offset: 3px;
  border-radius: 4px;
}

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

body {
  font-family: var(--font-sans);
  background-color: var(--bg);
  color: var(--text-main);
  line-height: 1.6;
  padding: 0 clamp(1rem, 5vw, 2rem);
  -webkit-font-smoothing: antialiased;
  transition: background-color 0.3s ease, color 0.3s ease;
}

/* ==========================================================================
   Layout
   ========================================================================== */

.container {
  max-width: 760px;
  margin: 0 auto;
  padding: 1.5rem 0 6rem;
}

button {
  background: none;
  border: none;
  font: inherit;
  color: inherit;
  cursor: pointer;
  text-align: left;
}

/* ==========================================================================
   Top Navigation & Theme Toggle
   ========================================================================== */

.top-nav {
  display: flex;
  justify-content: flex-end;
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
}

.theme-toggle {
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text-secondary);
  border-radius: 8px;
  padding: 0.5rem 0.625rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all 0.2s ease;
}

.theme-toggle:hover { background: var(--hover-bg); color: var(--text-main); }
.theme-toggle svg { width: 20px; height: 20px; }

.icon-sun, .icon-moon { display: none; }
[data-theme="light"] .icon-moon { display: block; }
[data-theme="dark"] .icon-sun { display: block; }

/* ==========================================================================
   Profile Header & Avatar
   ========================================================================== */

.avatar-wrapper {
  width: clamp(80px, 15vw, 96px);
  height: clamp(80px, 15vw, 96px);
  border-radius: 50%;
  overflow: hidden;
  margin-bottom: 1.5rem;
  background-color: var(--border);
  position: relative;
}

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

h1 { font-size: clamp(1.5rem, 5vw, 2rem); font-weight: 600; letter-spacing: -0.02em; margin-bottom: 0.5rem; line-height: 1.2; }
.tagline { font-size: clamp(1rem, 3vw, 1.15rem); color: var(--text-secondary); margin-bottom: 1.5rem; }

/* ==========================================================================
   Buttons & Links
   ========================================================================== */

.link-row { display: flex; gap: 0.75rem; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
  padding: 0.5rem clamp(0.75rem, 3vw, 0.875rem);
  border-radius: 8px;
  background: var(--bg);
  border: 1px solid var(--border);
  color: var(--text-main);
  font-size: clamp(0.8rem, 2vw, 0.875rem);
  font-weight: 500;
  text-decoration: none;
  transition: all 0.2s ease;
}

.btn:hover { background: var(--hover-bg); border-color: var(--text-secondary); }
.btn.primary { background: var(--email-btn-bg); color: var(--email-btn-text); border-color: var(--email-btn-bg); }
.btn.primary:hover { opacity: 0.85; background: var(--email-btn-bg); }

/* ==========================================================================
   Sections (Collapsible)
   ========================================================================== */

section {
  margin-top: clamp(3.5rem, 8vw, 4.5rem);
  opacity: 0;
  transform: translateY(20px);
  transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

section.visible { opacity: 1; transform: translateY(0); }

.section-header {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
  width: 100%;
  padding: 0.5rem 0;
}

.section-header:hover .section-title { color: var(--text-secondary); }
.section-title { font-size: 1rem; font-weight: 600; color: var(--text-main); transition: color 0.2s ease; white-space: nowrap; }
.section-header::after { content: ""; height: 1px; flex-grow: 1; background-color: var(--border); }

.chevron {
  width: 16px; height: 16px; fill: none; stroke: currentColor; stroke-width: 2;
  stroke-linecap: round; stroke-linejoin: round; transition: transform 0.3s ease; color: var(--text-secondary);
  flex-shrink: 0;
}

.section-header[aria-expanded="false"] .chevron { transform: rotate(-90deg); }

.section-content {
  overflow: hidden;
  transition: max-height 0.4s ease-in-out, opacity 0.3s ease-in-out;
  max-height: 2000px;
  opacity: 1;
  visibility: visible;
}

.section-content.collapsed-content {
  max-height: 0;
  opacity: 0;
  visibility: hidden;
}

/* ==========================================================================
   List Items (Projects, Experience)
   ========================================================================== */

.subsection-title {
  font-size: 0.875rem; text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-secondary);
  margin: 1.5rem 0 1rem; display: flex; align-items: center; justify-content: space-between;
}

.list-container { display: flex; flex-direction: column; gap: 0.5rem; }

.list-item {
  display: flex; justify-content: space-between; align-items: baseline;
  padding: 0.5rem; border-radius: 8px; width: 100%;
  transition: background 0.2s ease; margin: 0.5rem 0;
}

.list-item:hover { background: var(--hover-bg); }
.item-left { display: flex; flex-direction: column; gap: 0.5rem; max-width: 75%; }
.item-title { font-weight: 500; font-size: 1rem; line-height: 1.4; }
.item-desc { font-size: 0.875rem; color: var(--text-secondary); line-height: 1.4; }
.item-meta { font-size: 0.875rem; color: var(--text-secondary); white-space: nowrap; flex-shrink: 0; }

/* ==========================================================================
   About Section
   ========================================================================== */

.about-text { font-size: clamp(1rem, 2.5vw, 1.05rem); color: var(--text-secondary); line-height: 1.7; }
.about-text strong { color: var(--text-main); font-weight: 500; }

/* ==========================================================================
   Project Detail View
   ========================================================================== */

#home-view { display: block; }
#project-view { display: none; animation: fadeIn 0.4s ease-out; }

.sticky-nav {
  position: sticky; top: 0; background: var(--bg-alpha);
  backdrop-filter: blur(12px); -webkit-backdrop-filter: blur(12px);
  padding: clamp(1rem, 3vw, 1.5rem) 0; margin-bottom: clamp(1.5rem, 5vw, 2.5rem);
  border-bottom: 1px solid var(--border); z-index: 100; display: flex; align-items: center; gap: 0.5rem;
  font-size: clamp(0.85rem, 2vw, 0.95rem); white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
}

.back-btn {
  color: var(--text-secondary); display: flex; align-items: center; gap: 0.25rem;
  transition: color 0.2s ease; font-weight: 500; flex-shrink: 0;
}

.back-btn:hover { color: var(--text-main); }
.breadcrumb-title { color: var(--text-main); font-weight: 600; overflow: hidden; text-overflow: ellipsis; outline: none; }

.project-body h1 { font-size: clamp(1.75rem, 6vw, 2.5rem); margin-bottom: 1.5rem; line-height: 1.2; }
.project-body h2 { font-size: clamp(1.2rem, 4vw, 1.5rem); margin: 2.5rem 0 1rem; }
.project-body p { color: var(--text-secondary); font-size: clamp(1rem, 3vw, 1.1rem); margin-bottom: 1.25rem; }
.project-body ul { color: var(--text-secondary); font-size: clamp(1rem, 3vw, 1.1rem); margin-bottom: 1.25rem; padding-left: 1.5rem; }
.project-body li { margin-bottom: 0.5rem; }
.project-body figure {
  margin: 2rem 0;
}
.project-body img {
  width: 100%;
  height: auto;
  border-radius: 8px;
  border: 1px solid var(--border);
  display: block;
  background-color: var(--hover-bg);
  cursor: zoom-in;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}
.project-body img:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
}
[data-theme="dark"] .project-body img:hover {
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.6);
}
.project-body figcaption {
  font-size: 0.825rem;
  color: var(--text-secondary);
  margin-top: 0.5rem;
  text-align: center;
}

/* ==========================================================================
   Image Lightbox Modal
   ========================================================================== */

.image-modal {
  position: fixed;
  inset: 0;
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.25s ease, visibility 0.25s ease;
}

.image-modal.is-open {
  opacity: 1;
  visibility: visible;
}

.image-modal-backdrop {
  position: absolute;
  inset: 0;
  background-color: rgba(0, 0, 0, 0.88);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.image-modal-content {
  position: relative;
  z-index: 2;
  width: 100vw;
  height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 1rem;
}

.image-modal-close {
  position: absolute;
  top: 1rem;
  right: 1.25rem;
  z-index: 10;
  background: rgba(255, 255, 255, 0.15);
  border: 1px solid rgba(255, 255, 255, 0.25);
  color: #ffffff;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
}

.image-modal-close:hover {
  background: rgba(255, 255, 255, 0.3);
  transform: scale(1.05);
}

.image-modal-toolbar {
  position: absolute;
  bottom: 3.5rem;
  z-index: 10;
  display: flex;
  align-items: center;
  gap: 0.5rem;
  background: rgba(20, 20, 20, 0.85);
  border: 1px solid rgba(255, 255, 255, 0.15);
  padding: 0.35rem 0.75rem;
  border-radius: 9999px;
  color: #ffffff;
  backdrop-filter: blur(10px);
}

.modal-tool-btn {
  background: none;
  border: none;
  color: #ffffff;
  padding: 0.35rem 0.5rem;
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  border-radius: 6px;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background 0.15s ease;
}

.modal-tool-btn:hover {
  background: rgba(255, 255, 255, 0.2);
}

.modal-zoom-level {
  font-size: 0.8rem;
  font-weight: 600;
  min-width: 44px;
  text-align: center;
  user-select: none;
}

.image-modal-stage {
  flex: 1;
  width: 100%;
  max-width: 1400px;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  cursor: grab;
  touch-action: none;
}

.image-modal-stage.is-dragging {
  cursor: grabbing;
}

#modal-image {
  max-width: 90vw;
  max-height: 80vh;
  object-fit: contain;
  border-radius: 6px;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.5);
  transition: transform 0.1s ease-out;
  transform-origin: center center;
  user-select: none;
  -webkit-user-drag: none;
}

.image-modal-caption {
  position: absolute;
  bottom: 1rem;
  color: rgba(255, 255, 255, 0.75);
  font-size: 0.85rem;
  text-align: center;
  max-width: 80vw;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  pointer-events: none;
}

body.modal-open {
  overflow: hidden;
}
.project-body blockquote {
  border-left: 4px solid var(--focus-ring);
  padding-left: 1.5rem;
  margin: 2rem 0;
  font-size: 1.1rem;
  color: var(--text-main);
  font-style: italic;
}

/* ==========================================================================
   Project Navigation Footer
   ========================================================================== */

.project-nav-footer {
  display: flex; justify-content: space-between; margin-top: 5rem; padding-top: 2rem; border-top: 1px solid var(--border); gap: 1rem;
}

.nav-btn {
  display: flex; flex-direction: column; color: var(--text-main);
  transition: opacity 0.2s ease; max-width: 48%;
}

.nav-btn:hover { opacity: 0.7; }
.nav-btn.next { text-align: right; align-items: flex-end; }
.nav-label { font-size: clamp(0.7rem, 2vw, 0.8rem); text-transform: uppercase; letter-spacing: 0.05em; color: var(--text-secondary); margin-bottom: 0.5rem; }
.nav-title { font-weight: 500; font-size: clamp(0.85rem, 2.5vw, 0.95rem); line-height: 1.3; }

/* ==========================================================================
   Footer
   ========================================================================== */

.main-footer { margin-top: 5rem; padding-top: 2rem; border-top: 1px solid var(--border); display: flex; flex-direction: column; gap: 1.5rem; }
.footer-meta { display: flex; flex-direction: column; gap: 0.5rem; }
.footer-location, .footer-contact, .footer-status, .footer-note {
  font-size: clamp(0.75rem, 2vw, 0.875rem);
  color: var(--text-secondary);
  line-height: 1.5;
}
.footer-email-link {
  color: var(--text-main);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color 0.2s ease;
}
.footer-email-link:hover {
  color: var(--focus-ring);
}

/* ==========================================================================
   Animations
   ========================================================================== */

@keyframes fadeIn { from { opacity: 0; transform: translateY(10px); } to { opacity: 1; transform: translateY(0); } }

/* ==========================================================================
   Responsive
   ========================================================================== */

@media (max-width: 550px) {
  .list-item { flex-direction: column; align-items: flex-start; gap: 0.5rem; }
  .item-left { max-width: 100%; }
  .item-meta { font-size: 0.8rem; opacity: 0.8; }
  .link-row { gap: 0.5rem; }
  .btn { width: 100%; justify-content: center; margin-bottom: 0.5rem; }
}

@media (min-width: 2000px) {
  html { font-size: 22px; }
  .container { max-width: 1000px; }
  .avatar-wrapper { width: 140px; height: 140px; }
}