/* ===================================================
   PORTFOLIO STYLESHEET
   - CSS custom properties for light/dark theming
   - Smooth scroll, transitions, hover states
   - Google Fonts: DM Serif Display + DM Sans
=================================================== */

@import url('https://fonts.googleapis.com/css2?family=DM+Serif+Display:ital@0;1&family=DM+Sans:opsz,wght@9..40,300;9..40,400;9..40,500;9..40,600&display=swap');

/* ===== CSS Variables — Light Theme ===== */
:root {
  --bg:                #f7f5f0;
  --bg-card:           #ffffff;
  --bg-header:         #1a1a2e;
  --text:              #1a1a2e;
  --text-muted:        #6b6b80;
  --accent:            #c9622f;
  --accent-hover:      #a84d22;
  --border:            #dddbd6;
  --placeholder-bg:    #f0ede8;
  --placeholder-border:#ccc9c3;
  --input-bg:          #ffffff;
  --shadow:            0 4px 24px rgba(0,0,0,0.07);
  --shadow-hover:      0 8px 32px rgba(0,0,0,0.13);
  --nav-link:          rgba(255,255,255,0.8);
  --transition:        0.25s ease;
}

/* ===== Dark Theme ===== */
[data-theme="dark"] {
  --bg:                #12121e;
  --bg-card:           #1c1c2e;
  --bg-header:         #0d0d1a;
  --text:              #e8e6e0;
  --text-muted:        #9090a8;
  --accent:            #e07845;
  --accent-hover:      #c9622f;
  --border:            #2e2e45;
  --placeholder-bg:    #1e1e30;
  --placeholder-border:#2e2e45;
  --input-bg:          #1e1e30;
  --shadow:            0 4px 24px rgba(0,0,0,0.4);
  --shadow-hover:      0 8px 32px rgba(0,0,0,0.6);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: 'DM Sans', sans-serif;
  font-size: 16px;
  background-color: var(--bg);
  color: var(--text);
  line-height: 1.7;
  transition: background-color var(--transition), color var(--transition);
}

a {
  color: var(--accent);
  text-decoration: none;
  transition: color var(--transition);
}
a:hover { color: var(--accent-hover); text-decoration: underline; }

h1, h2, h3 {
  font-family: 'DM Serif Display', serif;
  line-height: 1.2;
}

/* ===== Header ===== */
header {
  background-color: var(--bg-header);
  padding: 0 32px;
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 16px rgba(0,0,0,0.3);
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
  gap: 16px;
  transition: background-color var(--transition);
}

.header-name {
  font-family: 'DM Serif Display', serif;
  font-size: 1.25rem;
  color: #fff;
  white-space: nowrap;
}

nav ul {
  list-style: none;
  display: flex;
  gap: 4px;
  align-items: center;
}

nav ul li a {
  color: var(--nav-link);
  font-size: 0.88rem;
  font-weight: 500;
  padding: 6px 12px;
  border-radius: 6px;
  transition: background var(--transition), color var(--transition);
  text-decoration: none;
}
nav ul li a:hover,
nav ul li a.active {
  background: rgba(255,255,255,0.12);
  color: #fff;
  text-decoration: none;
}

/* ===== Theme Toggle Button ===== */
#theme-toggle {
  background: rgba(255,255,255,0.1);
  border: 1px solid rgba(255,255,255,0.2);
  color: #fff;
  width: 38px;
  height: 38px;
  border-radius: 50%;
  cursor: pointer;
  font-size: 1rem;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  transition: background var(--transition), transform 0.3s;
}
#theme-toggle:hover {
  background: rgba(255,255,255,0.2);
  transform: rotate(25deg);
}

/* ===== Page Hero ===== */
.page-hero {
  background: var(--bg-header);
  color: #fff;
  padding: 60px 32px 50px;
  border-bottom: 3px solid var(--accent);
  transition: background-color var(--transition);
}
.page-hero h1 { font-size: 2.5rem; margin-bottom: 10px; }
.page-hero p  { color: rgba(255,255,255,0.6); font-size: 1.05rem; }

/* ===== Main ===== */
main {
  max-width: 860px;
  margin: 0 auto;
  padding: 52px 24px 80px;
}

/* ===== Section fade-in on load ===== */
section {
  margin-bottom: 56px;
  opacity: 0;
  transform: translateY(20px);
  animation: fadeUp 0.5s ease forwards;
}
section:nth-child(1) { animation-delay: 0.05s; }
section:nth-child(2) { animation-delay: 0.15s; }
section:nth-child(3) { animation-delay: 0.25s; }
section:nth-child(4) { animation-delay: 0.35s; }

@keyframes fadeUp {
  to { opacity: 1; transform: translateY(0); }
}

section h2 {
  font-size: 1.5rem;
  color: var(--text);
  padding-bottom: 10px;
  margin-bottom: 20px;
  border-bottom: 2px solid var(--accent);
}

/* ===== Cards ===== */
.card {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 24px 28px;
  margin-bottom: 16px;
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
}
.card:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px);
  border-color: var(--accent);
}
.card-title    { font-family: 'DM Serif Display', serif; font-size: 1.1rem; margin-bottom: 3px; }
.card-subtitle { color: var(--accent); font-size: 0.9rem; font-weight: 500; margin-bottom: 3px; }
.card-date     { color: var(--text-muted); font-size: 0.82rem; margin-bottom: 12px; }
.card ul       { padding-left: 20px; color: var(--text-muted); font-size: 0.93rem; }
.card ul li    { margin-bottom: 5px; }

/* ===== Placeholder blocks ===== */
.placeholder {
  background-color: var(--placeholder-bg);
  border: 1px dashed var(--placeholder-border);
  border-radius: 8px;
  padding: 20px 24px;
  color: var(--text-muted);
  font-style: italic;
  font-size: 0.93rem;
  line-height: 1.9;
}

/* ===== Skill Tags ===== */
.tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 10px; }
.tag {
  background: var(--placeholder-bg);
  border: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.8rem;
  font-weight: 500;
  padding: 4px 14px;
  border-radius: 20px;
  cursor: default;
  transition: background var(--transition), color var(--transition), border-color var(--transition);
}
.tag:hover {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* ===== Buttons ===== */
.btn {
  display: inline-block;
  padding: 8px 20px;
  border-radius: 7px;
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  text-decoration: none;
  transition: background var(--transition), color var(--transition), transform 0.15s, box-shadow 0.15s;
}
.btn:hover { transform: translateY(-1px); text-decoration: none; }

.btn-primary {
  background: var(--accent);
  color: #fff;
  border: 2px solid var(--accent);
}
.btn-primary:hover {
  background: var(--accent-hover);
  border-color: var(--accent-hover);
  color: #fff;
  box-shadow: 0 4px 12px rgba(201,98,47,0.35);
}
.btn-outline {
  background: transparent;
  color: var(--accent);
  border: 2px solid var(--accent);
}
.btn-outline:hover {
  background: var(--accent);
  color: #fff;
}

.project-links { margin-top: 16px; display: flex; gap: 12px; flex-wrap: wrap; }

/* ===== Contact Info Grid ===== */
.contact-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(170px, 1fr));
  gap: 16px;
}
.contact-item {
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 20px 16px;
  text-align: center;
  box-shadow: var(--shadow);
  transition: box-shadow var(--transition), transform var(--transition), border-color var(--transition);
}
.contact-item:hover {
  box-shadow: var(--shadow-hover);
  transform: translateY(-3px);
  border-color: var(--accent);
}
.contact-item .icon  { font-size: 1.7rem; margin-bottom: 8px; }
.contact-item .label { font-size: 0.72rem; font-weight: 600; letter-spacing: 0.09em; text-transform: uppercase; color: var(--text-muted); margin-bottom: 5px; }
.contact-item a      { font-size: 0.88rem; font-weight: 500; }

/* ===== Contact Form ===== */
.form-group { margin-bottom: 20px; }
.form-group label {
  display: block;
  font-size: 0.82rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 7px;
}
.form-group input,
.form-group textarea {
  width: 100%;
  padding: 12px 16px;
  background: var(--input-bg);
  border: 1.5px solid var(--border);
  border-radius: 8px;
  color: var(--text);
  font-family: 'DM Sans', sans-serif;
  font-size: 0.95rem;
  outline: none;
  transition: border-color var(--transition), box-shadow var(--transition), background var(--transition);
}
.form-group input:focus,
.form-group textarea:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(201,98,47,0.15);
}
.form-group input.invalid,
.form-group textarea.invalid {
  border-color: #d9534f;
  box-shadow: 0 0 0 3px rgba(217,83,79,0.12);
}
.form-group input.valid,
.form-group textarea.valid {
  border-color: #3aaa6b;
}
.form-group textarea { resize: vertical; min-height: 130px; }

.field-error {
  color: #d9534f;
  font-size: 0.8rem;
  margin-top: 5px;
  display: none;
}
.field-error.visible { display: block; }

.form-status {
  padding: 14px 18px;
  border-radius: 8px;
  font-size: 0.93rem;
  font-weight: 500;
  margin-top: 16px;
  display: none;
}
.form-status.success {
  background: #d4edda;
  color: #155724;
  border: 1px solid #c3e6cb;
  display: block;
}
.form-status.error {
  background: #f8d7da;
  color: #721c24;
  border: 1px solid #f5c6cb;
  display: block;
}

#submit-btn {
  border: none;
  font-family: 'DM Sans', sans-serif;
  font-size: 0.95rem;
  padding: 12px 36px;
}
#submit-btn:disabled {
  opacity: 0.65;
  cursor: not-allowed;
  transform: none !important;
}

/* ===== Scroll-to-top ===== */
#scroll-top {
  position: fixed;
  bottom: 28px;
  right: 28px;
  width: 44px;
  height: 44px;
  background: var(--accent);
  color: #fff;
  border: none;
  border-radius: 50%;
  font-size: 1.1rem;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 16px rgba(0,0,0,0.22);
  opacity: 0;
  pointer-events: none;
  transform: translateY(10px);
  transition: opacity 0.3s, transform 0.3s, background 0.2s;
  z-index: 200;
}
#scroll-top.visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}
#scroll-top:hover { background: var(--accent-hover); }

/* ===== Footer ===== */
footer {
  background-color: var(--bg-header);
  color: rgba(255,255,255,0.45);
  text-align: center;
  padding: 24px 16px;
  font-size: 0.85rem;
  transition: background-color var(--transition);
}
footer a { color: rgba(255,255,255,0.65); }
footer a:hover { color: #fff; text-decoration: none; }

/* ===== Responsive ===== */
@media (max-width: 620px) {
  .header-name { font-size: 1rem; }
  header { padding: 0 12px; gap: 8px; }
  nav ul { gap: 0; }
  nav ul li a { padding: 5px 7px; font-size: 0.78rem; }
  .page-hero { padding: 40px 20px 34px; }
  .page-hero h1 { font-size: 1.9rem; }
  main { padding: 32px 16px 60px; }
  .contact-grid { grid-template-columns: 1fr 1fr; }
}