:root {
  --bg: #f5f7fc;
  --surface: #ffffff;
  --surface-2: #edf1f9;
  --text: #141c36;
  --text-soft: #59637d;
  --accent: #3b5bfd;
  --accent-2: #8b34e8;
  --accent-3: #00b8d9;
  --accent-soft: rgba(59, 91, 253, 0.10);
  --border: #dde3f0;
  --ok: #0f9d58;
  --warn: #d93025;
  --shadow: 0 10px 30px rgba(20, 28, 54, 0.08);
  --radius: 16px;
  --wire: rgba(59, 91, 253, 0.55);
}
[data-theme="dark"] {
  --bg: #090d1c;
  --surface: #121830;
  --surface-2: #1a2140;
  --text: #edf1fb;
  --text-soft: #97a2c2;
  --accent: #6d8bff;
  --accent-2: #b06cff;
  --accent-3: #22d3ee;
  --accent-soft: rgba(109, 139, 255, 0.14);
  --border: #253058;
  --shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
  --wire: rgba(109, 139, 255, 0.65);
}
* { margin: 0; padding: 0; box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  font-family: "Segoe UI", system-ui, -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.6;
  transition: background 0.3s, color 0.3s;
  overflow-x: hidden;
}

/* ---------- Kaydırma ilerleme çubuğu ---------- */
#scrollBar {
  position: fixed; top: 0; left: 0; height: 3px; width: 0%;
  background: linear-gradient(90deg, var(--accent), var(--accent-2), var(--accent-3));
  z-index: 200; transition: width 0.1s linear;
}

/* ---------- Üst Menü ---------- */
header {
  position: sticky; top: 0; z-index: 100;
  backdrop-filter: blur(16px);
  background: color-mix(in srgb, var(--bg) 78%, transparent);
  border-bottom: 1px solid var(--border);
}
nav {
  max-width: 1200px; margin: 0 auto; padding: 0.65rem 1.2rem;
  display: flex; align-items: center; gap: 0.8rem; flex-wrap: wrap;
}
.logo { display: flex; align-items: center; gap: 0.55rem; cursor: pointer; user-select: none; }
.logo svg { width: 34px; height: 34px; flex: none; }
.logo .word { font-weight: 800; font-size: 1.18rem; letter-spacing: -0.02em; }
.logo .word span {
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.nav-links { display: flex; gap: 0.1rem; margin-left: auto; flex-wrap: wrap; }
.nav-links a {
  color: var(--text-soft); text-decoration: none; font-size: 0.86rem;
  padding: 0.4rem 0.6rem; border-radius: 8px; transition: 0.2s;
}
.nav-links a:hover { color: var(--accent); background: var(--accent-soft); }
.mode-pill {
  border: 1px solid var(--border); background: var(--surface); color: var(--text);
  border-radius: 999px; padding: 0.35rem 0.85rem; cursor: pointer;
  font-size: 0.8rem; font-weight: 700; transition: 0.2s; display: none; font-family: inherit;
}
.mode-pill.show { display: inline-block; }
.mode-pill:hover { border-color: var(--accent); color: var(--accent); }
#authSlot { display: flex; align-items: center; gap: 0.6rem; }
.auth-name {
  font-size: 0.85rem; font-weight: 700; color: var(--text);
  background: var(--accent-soft); border-radius: 999px; padding: 0.35rem 0.85rem;
  white-space: nowrap; text-decoration: none; transition: 0.2s;
}
.auth-name:hover { background: var(--accent); color: #fff; }
/* Netlify Identity widget modalini site temasina uydur */
.netlify-identity-widget-overlay { backdrop-filter: blur(4px); }
#themeBtn {
  border: 1px solid var(--border); background: var(--surface);
  color: var(--text); border-radius: 10px; padding: 0.4rem 0.7rem;
  cursor: pointer; font-size: 1rem; transition: 0.2s;
}
#themeBtn:hover { border-color: var(--accent); }

/* ---------- Butonlar ---------- */
.btn {
  display: inline-block; text-decoration: none; font-weight: 600; text-align: center;
  padding: 0.75rem 1.5rem; border-radius: 12px; font-size: 0.95rem;
  transition: transform 0.15s, box-shadow 0.15s; cursor: pointer; border: none;
  color: var(--text); font-family: inherit;
}
.btn:active { transform: scale(0.97); }
.btn-primary {
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  color: #fff; box-shadow: 0 6px 20px rgba(59, 91, 253, 0.35);
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 26px rgba(59, 91, 253, 0.45); }
.btn-ghost { background: var(--surface); color: var(--text); border: 1px solid var(--border); }
.btn-ghost:hover { border-color: var(--accent); color: var(--accent); }

/* ---------- Hero (3D sahne) ---------- */
.hero {
  position: relative; overflow: hidden;
  max-width: 1200px; margin: 0 auto;
  padding: 4.5rem 1.2rem 3rem;
  display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 2rem; align-items: center;
  min-height: 460px;
}
@media (max-width: 880px) {
  .hero { grid-template-columns: 1fr; padding-top: 3rem; min-height: 0; }
  .hero-3d { order: -1; height: 240px; opacity: 0.9; }
}
.hero::before {
  content: ""; position: absolute; inset: -40% -20%;
  background:
    radial-gradient(600px 340px at 20% 10%, var(--accent-soft), transparent 70%),
    radial-gradient(700px 380px at 85% 30%, rgba(139, 52, 232, 0.12), transparent 70%),
    radial-gradient(500px 300px at 60% 90%, rgba(0, 184, 217, 0.10), transparent 70%);
  pointer-events: none; animation: blobFloat 16s ease-in-out infinite alternate;
}
@keyframes blobFloat { from { transform: translate3d(0,0,0) scale(1); } to { transform: translate3d(2%, 3%, 0) scale(1.06); } }
.hero-grid {
  position: absolute; inset: 0; pointer-events: none; opacity: 0.45;
  background-image:
    linear-gradient(var(--border) 1px, transparent 1px),
    linear-gradient(90deg, var(--border) 1px, transparent 1px);
  background-size: 44px 44px;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 35%, black 25%, transparent 75%);
  -webkit-mask-image: radial-gradient(ellipse 80% 70% at 50% 35%, black 25%, transparent 75%);
}
.hero-copy { position: relative; z-index: 2; }
.hero-badge {
  display: inline-block; background: var(--accent-soft); color: var(--accent);
  padding: 0.35rem 0.9rem; border-radius: 999px;
  font-size: 0.82rem; font-weight: 600; margin-bottom: 1.1rem;
  border: 1px solid color-mix(in srgb, var(--accent) 25%, transparent);
}
.hero-copy h1 {
  font-size: clamp(2.1rem, 5vw, 3.4rem); font-weight: 800;
  letter-spacing: -0.03em; line-height: 1.08; margin-bottom: 0.9rem;
}
.hero-copy h1 em {
  font-style: normal;
  background: linear-gradient(90deg, var(--accent), var(--accent-2), var(--accent-3));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.hero-copy p { color: var(--text-soft); font-size: 1.06rem; max-width: 520px; margin-bottom: 1.6rem; }
.hero-actions { display: flex; gap: 0.8rem; flex-wrap: wrap; }
.hero-3d { position: relative; z-index: 1; height: 380px; }
#heroCanvas { width: 100%; height: 100%; display: block; }
.hero-3d .hint3d {
  position: absolute; bottom: 4px; left: 50%; transform: translateX(-50%);
  font-size: 0.72rem; color: var(--text-soft); opacity: 0.7; white-space: nowrap;
}

/* ---------- Reklam Alanları ---------- */
.ad-slot {
  max-width: 1200px; margin: 0.6rem auto; padding: 0 1.2rem;
}
.ad-inner {
  position: relative; display: flex; align-items: center; justify-content: center;
  min-height: 90px; border: 1px dashed var(--border); border-radius: 12px;
  background: repeating-linear-gradient(45deg, var(--surface), var(--surface) 12px, var(--surface-2) 12px, var(--surface-2) 24px);
  color: var(--text-soft); font-size: 0.85rem; overflow: hidden;
}
.ad-inner::before {
  content: "REKLAM"; position: absolute; top: 6px; left: 10px;
  font-size: 0.62rem; font-weight: 700; letter-spacing: 0.14em; color: var(--text-soft); opacity: 0.7;
}
.ad-inner span { opacity: 0.75; padding: 1rem; text-align: center; }

/* ---------- Landing / Kurucu ---------- */
.landing { position: relative; max-width: 1200px; margin: 0 auto; padding: 2.5rem 1.2rem 3rem; }
.founder-card {
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  backdrop-filter: blur(8px);
  border: 1px solid var(--border);
  border-radius: 22px; box-shadow: var(--shadow);
  padding: 1.9rem; display: grid; grid-template-columns: auto 1fr; gap: 1.6rem;
  align-items: start; margin-bottom: 2.6rem;
  transform-style: preserve-3d; will-change: transform;
}
@media (max-width: 720px) { .founder-card { grid-template-columns: 1fr; text-align: center; } }
.founder-avatar {
  width: 112px; height: 112px; border-radius: 26px;
  background: conic-gradient(from 210deg, var(--accent), var(--accent-2), var(--accent-3), var(--accent));
  color: #fff; display: grid; place-items: center;
  font-size: 2.2rem; font-weight: 800;
  box-shadow: 0 12px 28px rgba(59, 91, 253, 0.35);
  margin: 0 auto; transform: translateZ(30px);
}
.founder-info h2 { font-size: 1.55rem; letter-spacing: -0.02em; }
.founder-role { color: var(--accent); font-weight: 700; font-size: 0.92rem; margin-bottom: 0.6rem; }
.founder-bio { color: var(--text-soft); font-size: 0.95rem; margin-bottom: 0.9rem; }
.founder-tags { display: flex; flex-wrap: wrap; gap: 0.45rem; margin-bottom: 1.1rem; justify-content: inherit; }
.founder-tags span {
  background: var(--accent-soft); color: var(--accent);
  font-size: 0.76rem; font-weight: 700; padding: 0.25rem 0.7rem; border-radius: 999px;
}
.pub-head { font-size: 0.82rem; font-weight: 800; text-transform: uppercase; letter-spacing: 0.1em; color: var(--text-soft); margin-bottom: 0.5rem; }
.pub-list { display: grid; gap: 0.55rem; }
.pub-item {
  display: block; text-decoration: none; color: var(--text);
  background: var(--surface-2); border: 1px solid var(--border);
  border-radius: 12px; padding: 0.7rem 0.95rem; font-size: 0.85rem;
  transition: 0.2s; text-align: left; position: relative;
}
.pub-item:hover { border-color: var(--accent); transform: translateX(4px); }
.pub-item b { display: block; font-size: 0.86rem; padding-right: 4.5rem; }
.pub-item small { color: var(--text-soft); }
.pub-item .intl {
  position: absolute; top: 0.65rem; right: 0.7rem;
  background: linear-gradient(90deg, var(--accent), var(--accent-2)); color: #fff;
  font-size: 0.62rem; font-weight: 800; letter-spacing: 0.06em;
  padding: 0.18rem 0.5rem; border-radius: 999px;
}
.founder-links { margin-top: 1rem; display: flex; gap: 0.6rem; flex-wrap: wrap; justify-content: inherit; }
.founder-links a {
  font-size: 0.82rem; font-weight: 700; color: var(--accent);
  text-decoration: none; border: 1px solid var(--border);
  padding: 0.38rem 0.85rem; border-radius: 999px; transition: 0.2s;
  background: var(--surface);
}
.founder-links a:hover { background: var(--accent-soft); border-color: var(--accent); transform: translateY(-2px); }

/* ---------- Mod seçimi + 3D küp ---------- */
.mode-select { text-align: center; position: relative; }
.mode-select h2 { font-size: 1.6rem; letter-spacing: -0.02em; margin-bottom: 0.4rem; }
.mode-select > p { color: var(--text-soft); margin-bottom: 1.8rem; }
.cube-scene { width: 90px; height: 90px; margin: 0 auto 2.2rem; perspective: 500px; }
.cube {
  width: 100%; height: 100%; position: relative;
  transform-style: preserve-3d; animation: cubeSpin 14s linear infinite;
}
.cube-face {
  position: absolute; inset: 0; display: grid; place-items: center;
  font-size: 2.1rem; border-radius: 14px;
  background: color-mix(in srgb, var(--surface) 72%, transparent);
  border: 1px solid color-mix(in srgb, var(--accent) 35%, var(--border));
  box-shadow: inset 0 0 24px var(--accent-soft);
}
.cube-face:nth-child(1) { transform: rotateY(0deg) translateZ(45px); }
.cube-face:nth-child(2) { transform: rotateY(90deg) translateZ(45px); }
.cube-face:nth-child(3) { transform: rotateY(180deg) translateZ(45px); }
.cube-face:nth-child(4) { transform: rotateY(270deg) translateZ(45px); }
.cube-face:nth-child(5) { transform: rotateX(90deg) translateZ(45px); }
.cube-face:nth-child(6) { transform: rotateX(-90deg) translateZ(45px); }
@keyframes cubeSpin {
  from { transform: rotateX(-16deg) rotateY(0deg); }
  to { transform: rotateX(-16deg) rotateY(360deg); }
}
.mode-btns { display: grid; grid-template-columns: 1fr 1fr; gap: 1.2rem; max-width: 780px; margin: 0 auto; }
@media (max-width: 640px) { .mode-btns { grid-template-columns: 1fr; } }
.mode-btn {
  background: var(--surface); border: 2px solid var(--border);
  border-radius: 18px; padding: 1.8rem 1.4rem; cursor: pointer;
  text-align: center; transition: border-color 0.2s, background 0.2s; box-shadow: var(--shadow);
  color: var(--text); font-family: inherit;
  transform-style: preserve-3d; will-change: transform;
}
.mode-btn:hover { border-color: var(--accent); }
.mode-btn.selected { border-color: var(--accent); background: var(--accent-soft); }
.mode-btn .m-icon { font-size: 2.4rem; display: block; margin-bottom: 0.6rem; transform: translateZ(26px); }
.mode-btn .m-title { font-size: 1.2rem; font-weight: 800; display: block; margin-bottom: 0.35rem; transform: translateZ(18px); }
.mode-btn .m-desc { font-size: 0.86rem; color: var(--text-soft); display: block; }

/* ---------- Genel Bölüm ---------- */
section { max-width: 1200px; margin: 0 auto; padding: 3.2rem 1.2rem; }
.section-head { text-align: center; margin-bottom: 2.2rem; }
.section-head h2 { font-size: 1.9rem; font-weight: 800; letter-spacing: -0.02em; }
.section-head p { color: var(--text-soft); max-width: 620px; margin: 0.5rem auto 0; }
.kicker {
  color: var(--accent); font-size: 0.8rem; font-weight: 700;
  text-transform: uppercase; letter-spacing: 0.14em;
}
.card {
  background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); box-shadow: var(--shadow);
  padding: 1.6rem;
}
.hidden { display: none !important; }

/* ---------- Disiplin + Araç seçici ---------- */
.disc-tabs { display: flex; gap: 0.5rem; flex-wrap: wrap; justify-content: center; margin-bottom: 1.2rem; }
.disc-tab {
  border: 1px solid var(--border); background: var(--surface); color: var(--text-soft);
  border-radius: 999px; padding: 0.5rem 1.1rem; cursor: pointer;
  font-size: 0.9rem; font-weight: 600; transition: 0.2s; font-family: inherit;
}
.disc-tab:hover { border-color: var(--accent); color: var(--accent); transform: translateY(-2px); }
.disc-tab.active {
  background: linear-gradient(90deg, var(--accent), var(--accent-2));
  color: #fff; border-color: transparent;
}
.tool-chips { display: flex; gap: 0.45rem; flex-wrap: wrap; justify-content: center; margin-bottom: 1.5rem; }
.tool-chip {
  border: 1px dashed var(--border); background: var(--surface-2); color: var(--text-soft);
  border-radius: 10px; padding: 0.42rem 0.85rem; cursor: pointer;
  font-size: 0.84rem; font-weight: 600; transition: 0.2s; font-family: inherit;
}
.tool-chip:hover { border-color: var(--accent); color: var(--accent); }
.tool-chip.active { background: var(--accent-soft); color: var(--accent); border: 1px solid var(--accent); }
.tool-stage { animation: stageIn 0.45s cubic-bezier(0.2, 0.7, 0.3, 1); }
@keyframes stageIn {
  from { opacity: 0; transform: perspective(900px) rotateX(6deg) translateY(18px); }
  to { opacity: 1; transform: perspective(900px) rotateX(0) translateY(0); }
}
.tool-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 1.4rem; align-items: start; }
@media (max-width: 820px) { .tool-grid { grid-template-columns: 1fr; } }
.tool-title { font-size: 1.1rem; font-weight: 800; margin-bottom: 0.2rem; }
.tool-sub { font-size: 0.85rem; color: var(--text-soft); margin-bottom: 0.8rem; }
.tool-src {
  margin-top: 1.1rem; padding-top: 0.8rem; border-top: 1px dashed var(--border);
  font-size: 0.78rem; color: var(--text-soft);
}
.tool-src a { color: var(--accent); text-decoration: none; font-weight: 700; }
.tool-src a:hover { text-decoration: underline; }

label { display: block; font-size: 0.85rem; font-weight: 600; color: var(--text-soft); margin: 0.85rem 0 0.3rem; }
input[type="number"], input[type="text"], input[type="email"], select, textarea {
  width: 100%; padding: 0.62rem 0.85rem; border-radius: 10px;
  border: 1px solid var(--border); background: var(--surface-2);
  color: var(--text); font-size: 0.95rem; outline: none; transition: 0.2s;
  font-family: inherit;
}
textarea { resize: vertical; min-height: 110px; }
input:focus, select:focus, textarea:focus { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.in-row { display: grid; grid-template-columns: 1fr 1fr; gap: 0 0.8rem; }

.result-box {
  background: var(--surface-2); border: 1px dashed var(--border);
  border-radius: 12px; padding: 1rem 1.2rem; margin-top: 1rem;
}
.result-line { display: flex; justify-content: space-between; gap: 1rem; padding: 0.32rem 0; font-size: 0.94rem; flex-wrap: wrap; }
.result-line b { color: var(--accent); font-variant-numeric: tabular-nums; text-align: right; }
.hint { font-size: 0.8rem; color: var(--text-soft); margin-top: 0.8rem; }
.hint code { background: var(--surface-2); padding: 0.1rem 0.4rem; border-radius: 6px; }
.formula-note { font-family: Cambria, Georgia, serif; font-size: 0.95rem; color: var(--text-soft); margin-top: 0.6rem; }

/* ---------- Makine Elemanları ---------- */
.me-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1.1rem; }
.me-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: 16px;
  padding: 1.3rem; box-shadow: var(--shadow); position: relative; overflow: hidden;
  transform-style: preserve-3d; will-change: transform; transition: border-color 0.2s;
}
.me-card:hover { border-color: color-mix(in srgb, var(--accent) 45%, var(--border)); }
.me-card::after {
  content: ""; position: absolute; top: -40px; right: -40px; width: 110px; height: 110px;
  border-radius: 50%; background: var(--accent-soft); opacity: 0.7;
}
.me-card .me-icon { font-size: 1.9rem; margin-bottom: 0.5rem; display: inline-block; transform: translateZ(24px); }
.me-card h3 { font-size: 1.02rem; margin-bottom: 0.4rem; transform: translateZ(16px); }
.me-card p { font-size: 0.85rem; color: var(--text-soft); margin-bottom: 0.7rem; }
.me-formula {
  font-family: Cambria, Georgia, serif; font-size: 0.95rem; color: var(--accent);
  background: var(--accent-soft); border-radius: 8px; padding: 0.4rem 0.7rem;
  display: inline-block; margin-bottom: 0.6rem;
}
.me-std { font-size: 0.74rem; color: var(--text-soft); }
.me-std b { color: var(--text); }
.me-refs { font-size: 0.74rem; margin-top: 0.3rem; }
.me-refs a { color: var(--accent); text-decoration: none; font-weight: 700; }

/* ---------- Tasarım İpuçları ---------- */
.tips-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(300px, 1fr)); gap: 1rem; counter-reset: tip; }
.tip-card {
  background: var(--surface); border: 1px solid var(--border); border-radius: 14px;
  padding: 1.1rem 1.2rem 1.1rem 3.4rem; position: relative; box-shadow: var(--shadow);
  font-size: 0.88rem; transition: transform 0.2s;
}
.tip-card:hover { transform: translateY(-3px); }
.tip-card::before {
  counter-increment: tip; content: counter(tip, decimal-leading-zero);
  position: absolute; left: 0.9rem; top: 1rem;
  font-size: 1.15rem; font-weight: 800;
  background: linear-gradient(135deg, var(--accent), var(--accent-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}
.tip-card .t-cat {
  display: inline-block; font-size: 0.68rem; font-weight: 800; text-transform: uppercase;
  letter-spacing: 0.1em; color: var(--accent); background: var(--accent-soft);
  border-radius: 999px; padding: 0.12rem 0.55rem; margin-bottom: 0.4rem;
}
.tip-card p { color: var(--text-soft); }

/* ---------- Kaynak Kütüphanesi ---------- */
.res-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(250px, 1fr)); gap: 1rem; }
.res-card {
  display: block; text-decoration: none; color: var(--text);
  background: var(--surface); border: 1px solid var(--border); border-radius: 14px;
  padding: 1.1rem 1.2rem; box-shadow: var(--shadow); transition: 0.2s;
}
.res-card:hover { border-color: var(--accent); transform: translateY(-4px); }
.res-card .r-icon { font-size: 1.6rem; }
.res-card h3 { font-size: 0.98rem; margin: 0.4rem 0 0.2rem; }
.res-card p { font-size: 0.8rem; color: var(--text-soft); }

/* ---------- Kaynakça ---------- */
.biblio-list { display: grid; gap: 0.5rem; max-width: 900px; margin: 0 auto; }
.biblio-item {
  display: grid; grid-template-columns: auto 1fr auto; gap: 0.8rem; align-items: baseline;
  background: var(--surface); border: 1px solid var(--border); border-radius: 10px;
  padding: 0.6rem 0.9rem; font-size: 0.84rem; scroll-margin-top: 90px;
}
.biblio-item:target { border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.biblio-item .b-no { font-weight: 800; color: var(--accent); font-variant-numeric: tabular-nums; }
.biblio-item .b-txt { color: var(--text-soft); }
.biblio-item .b-txt i { color: var(--text); font-style: italic; }
.biblio-item a { color: var(--accent); text-decoration: none; font-weight: 700; font-size: 0.78rem; white-space: nowrap; }
.biblio-item a:hover { text-decoration: underline; }

/* ---------- Tablolar ---------- */
.table-wrap { overflow-x: auto; border: 1px solid var(--border); border-radius: 12px; margin-top: 1rem; }
table { width: 100%; border-collapse: collapse; font-size: 0.88rem; min-width: 640px; }
th, td { padding: 0.6rem 0.9rem; text-align: left; border-bottom: 1px solid var(--border); }
th { background: var(--surface-2); font-weight: 700; white-space: nowrap; }
tbody tr:hover { background: var(--accent-soft); }
td b { font-weight: 600; }
.table-src { font-size: 0.76rem; color: var(--text-soft); margin-top: 0.7rem; }
.table-src a { color: var(--accent); font-weight: 700; text-decoration: none; }

/* ---------- Formül Kartları ---------- */
.flash-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(240px, 1fr)); gap: 1rem; }
.flash { perspective: 900px; cursor: pointer; height: 170px; }
.flash-inner { position: relative; width: 100%; height: 100%; transition: transform 0.55s; transform-style: preserve-3d; }
.flash.flipped .flash-inner { transform: rotateY(180deg); }
.flash-face {
  position: absolute; inset: 0; backface-visibility: hidden;
  border-radius: 14px; border: 1px solid var(--border);
  display: flex; flex-direction: column; justify-content: center; align-items: center;
  text-align: center; padding: 1rem; gap: 0.4rem;
}
.flash-front { background: var(--surface); box-shadow: var(--shadow); }
.flash-front .f-title { font-weight: 700; }
.flash-front .f-cat { font-size: 0.75rem; color: var(--accent); font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; }
.flash-front .f-tip { font-size: 0.78rem; color: var(--text-soft); }
.flash-back { background: linear-gradient(135deg, var(--accent), var(--accent-2)); color: #fff; transform: rotateY(180deg); }
.flash-back .f-formula { font-size: 1.2rem; font-weight: 700; font-family: Cambria, Georgia, serif; }
.flash-back .f-desc { font-size: 0.8rem; opacity: 0.9; }

/* ---------- Quiz ---------- */
.quiz-card { max-width: 680px; margin: 0 auto; }
.quiz-progress { height: 6px; background: var(--surface-2); border-radius: 999px; overflow: hidden; margin-bottom: 1.4rem; }
.quiz-progress i { display: block; height: 100%; background: linear-gradient(90deg, var(--accent), var(--accent-2)); transition: width 0.35s; }
.quiz-q { font-size: 1.12rem; font-weight: 700; margin-bottom: 1.2rem; }
.quiz-opts { display: grid; gap: 0.7rem; }
.quiz-opt {
  text-align: left; padding: 0.85rem 1.1rem; border-radius: 12px;
  border: 1px solid var(--border); background: var(--surface-2);
  color: var(--text); cursor: pointer; font-size: 0.95rem; transition: 0.2s; font-family: inherit;
}
.quiz-opt:hover:not(:disabled) { border-color: var(--accent); background: var(--accent-soft); }
.quiz-opt.correct { border-color: var(--ok); background: rgba(15, 157, 88, 0.12); }
.quiz-opt.wrong { border-color: var(--warn); background: rgba(217, 48, 37, 0.10); }
.quiz-explain { margin-top: 1rem; padding: 0.9rem 1.1rem; border-radius: 12px; background: var(--accent-soft); font-size: 0.9rem; display: none; }
.quiz-footer { display: flex; justify-content: space-between; align-items: center; margin-top: 1.4rem; }
.quiz-score { text-align: center; padding: 2rem 1rem; }
.quiz-score b { font-size: 3rem; color: var(--accent); display: block; }

/* ---------- SVG şema ---------- */
.beam-svg { width: 100%; height: auto; margin-top: 0.5rem; }
.beam-svg .stroke { stroke: var(--text); }
.beam-svg .soft { stroke: var(--text-soft); }
.beam-svg .load { stroke: var(--warn); fill: var(--warn); }
.beam-svg text { fill: var(--text-soft); font-size: 11px; font-family: inherit; }

/* Direnç renk kodu */
.res-body { display: flex; align-items: center; justify-content: center; gap: 0; margin: 1rem 0; }
.res-wire { height: 4px; width: 34px; background: var(--text-soft); }
.res-shell {
  display: flex; align-items: center; gap: 9px; padding: 0 14px;
  height: 52px; border-radius: 14px; background: #d9c9a3; border: 1px solid #b7a67e;
}
.res-band { width: 9px; height: 100%; }

.badge-ok { color: var(--ok); font-weight: 700; }
.badge-warn { color: var(--warn); font-weight: 700; }

footer {
  border-top: 1px solid var(--border); margin-top: 2rem;
  padding: 2.4rem 1.2rem; text-align: center; color: var(--text-soft); font-size: 0.88rem;
}
footer .f-logo { display: flex; justify-content: center; margin-bottom: 0.6rem; }
footer .f-logo svg { width: 40px; height: 40px; }

/* ---------- Görünüm animasyonları ---------- */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity 0.65s ease, transform 0.65s ease; }
.reveal.visible { opacity: 1; transform: none; }
.stagger > * { opacity: 0; transform: translateY(22px); transition: opacity 0.55s ease, transform 0.55s ease; }
.stagger.visible > * { opacity: 1; transform: none; }
.stagger.visible > *:nth-child(1) { transition-delay: 0.03s; }
.stagger.visible > *:nth-child(2) { transition-delay: 0.09s; }
.stagger.visible > *:nth-child(3) { transition-delay: 0.15s; }
.stagger.visible > *:nth-child(4) { transition-delay: 0.21s; }
.stagger.visible > *:nth-child(5) { transition-delay: 0.27s; }
.stagger.visible > *:nth-child(6) { transition-delay: 0.33s; }
.stagger.visible > *:nth-child(7) { transition-delay: 0.39s; }
.stagger.visible > *:nth-child(8) { transition-delay: 0.45s; }
.stagger.visible > *:nth-child(n+9) { transition-delay: 0.5s; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .reveal, .stagger > * { opacity: 1; transform: none; transition: none; }
  .flash-inner { transition: none; }
  .cube { animation: none; transform: rotateX(-16deg) rotateY(30deg); }
  .hero::before { animation: none; }
}