:root {
  --bg: #0a0c0a; --card-bg: #111411; --text: #e0ffe0; --text-muted: #7caa7c;
  --accent: #00ff41; --accent-dark: #008f25; --accent-glow: rgba(0,255,65,0.25);
  --accent-rgb: 0,255,65;
  --border: #2a332a; --input-bg: #0d100d; --input-border: #3a453a;
  --hover-bg: #1a1f1a; --font-main: 'Consolas','Fira Code','Segoe UI',monospace;
}
* { box-sizing: border-box; }
body {
  font-family: var(--font-main); background: var(--bg); color: var(--text);
  display: flex; justify-content: center; align-items: flex-start;
  min-height: 100vh; margin: 0; padding: 30px 10px;
  background-image: radial-gradient(var(--border) 1px, transparent 1px); background-size: 20px 20px;
}
.container {
  background: var(--card-bg); padding: 2rem; border-radius: 12px;
  box-shadow: 0 0 25px var(--accent-glow), 0 10px 40px rgba(0,0,0,0.7);
  width: 100%; max-width: 700px; border: 1px solid var(--accent-dark);
}

/* === HEADER & NAV === */
.header {
  display: flex; flex-direction: column; align-items: center;
  border-bottom: 1px solid var(--border); padding-bottom: 15px; margin-bottom: 20px;
}
.header h2 { margin: 0 0 12px 0; }
.header-row {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 12px; align-items: center;
  width: 100%;
}
.lang-switch { display: flex; align-items: center; gap: 8px; }
.lang-link {
  background: transparent; border: none; color: var(--text-muted); cursor: pointer;
  padding: 4px 10px; border-radius: 6px; transition: 0.2s; font-size: 0.85rem; font-weight: 500;
  font-family: var(--font-main); text-decoration: none;
}
.lang-link:hover, .lang-link.active { color: var(--accent); background: var(--hover-bg); font-weight: bold; }

/* === TABURI PRINCIPALE === */
.main-tabs {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 6px;
  padding: 8px 0; border-bottom: 2px solid var(--border); margin-bottom: 10px;
}
.m-tab {
  flex: 1 1 calc(25% - 10px); min-width: 80px; max-width: 200px;
  background: transparent; border: none; color: var(--text-muted); cursor: pointer;
  font-family: var(--font-main); font-size: 0.82rem; padding: 8px 6px; border-radius: 6px;
  transition: 0.2s; text-transform: uppercase; letter-spacing: 0.5px; text-align: center; white-space: nowrap;
}
.m-tab:hover { color: var(--text); background: var(--hover-bg); }
.m-tab.active { color: var(--accent); background: var(--hover-bg); box-shadow: 0 0 8px var(--accent-glow); font-weight: bold; }
/* 🌓 Butonul de temă în navbar - stil tab, dar distinct vizual */
.theme-toggle-btn {
  background: var(--hover-bg) !important;
  border: 1px dashed var(--accent-dark) !important;
  color: var(--accent) !important;
  font-weight: 600;
  letter-spacing: 0;
  text-transform: none;
}
.theme-toggle-btn:hover {
  background: var(--accent) !important;
  color: #000 !important;
  border-style: solid !important;
}

/* === TABURI SECUNDARE === */
.sub-tabs { display: flex; flex-wrap: wrap; gap: 6px; margin-bottom: 15px; padding: 8px 0; border-bottom: 1px dashed var(--border); min-height: 40px; }
.s-tab {
  background: var(--input-bg); border: 1px solid var(--input-border); color: var(--text-muted);
  padding: 6px 12px; border-radius: 20px; cursor: pointer; font-size: 0.78rem; transition: 0.2s; display: none;
}
.s-tab.visible { display: inline-block; }
.s-tab:hover { border-color: var(--accent); color: var(--text); }
.s-tab.active { background: var(--accent); color: #000; border-color: var(--accent); font-weight: bold; box-shadow: 0 0 6px var(--accent-glow); }

/* === LINKURI EXTERNE HEADER === */
.header-ext-row {
  display: flex; flex-wrap: wrap; justify-content: center; gap: 10px; align-items: center;
}
.ext-btn {
  display: inline-flex; align-items: center; padding: 8px 14px;
  background: var(--hover-bg); border: 1px solid var(--border); border-radius: 8px;
  color: var(--text-muted); text-decoration: none; font-size: 0.84rem; font-weight: 500;
  transition: all 0.2s ease; white-space: nowrap;
}
.ext-btn:hover { background: var(--accent); color: #000; border-color: var(--accent); transform: translateY(-1px); }

/* === FORMULARE & BUTOANE === */
.input-group { margin-bottom: 12px; }
label { display: block; margin-bottom: 4px; color: var(--text); font-weight: 600; font-size: 0.82rem; }
input, select {
  width: 100%; padding: 10px; background: var(--input-bg); border: 2px solid var(--input-border);
  border-radius: 6px; font-size: 0.95rem; color: var(--text); transition: 0.2s; font-family: inherit;
}
input:focus, select:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 8px var(--accent-glow); }
.btn-group { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; margin-top: 15px; }
.btn-group-4 { grid-template-columns: 1fr 1fr 1fr 1fr; }
.btn-group-1 { grid-template-columns: 1fr; }
button {
  padding: 10px; border: 1px solid var(--accent-dark); border-radius: 6px; font-size: 0.88rem; font-weight: bold;
  cursor: pointer; transition: 0.2s; color: #000; background: var(--accent); text-transform: uppercase; letter-spacing: 0.5px;
}
button:hover { transform: translateY(-2px); filter: brightness(1.15); }
button:active { transform: translateY(0); }

/* === REZULTATE & LOADER === */
.result-box {
  margin-top: 20px; padding: 12px; background: var(--hover-bg); border-left: 4px solid var(--accent);
  border-radius: 6px; text-align: center; font-weight: bold; font-size: 1.05rem; color: var(--text);
  display: none; word-break: break-all; line-height: 1.6;
}
.loader { text-align: center; color: var(--text-muted); padding: 20px; animation: pulse 1s infinite; }
@keyframes pulse { 0%,100% { opacity:0.4 } 50% { opacity:1 } }

/* === TABEL === */
.table-wrap { margin-top: 15px; max-height: 350px; overflow-y: auto; border-radius: 6px; border: 1px solid var(--border); background: var(--input-bg); }
table { width: 100%; border-collapse: collapse; font-size: 0.88rem; }
thead th { background: var(--accent-dark); color: #000; padding: 7px 8px; text-align: center; position: sticky; top: 0; z-index: 2; font-weight: 800; }
tbody tr:nth-child(even) { background: rgba(var(--accent-rgb),0.04); }
tbody td { padding: 6px 8px; text-align: center; border-bottom: 1px solid var(--border); }
.badge { display: inline-block; padding: 2px 6px; border-radius: 8px; font-size: 0.72rem; background: rgba(var(--accent-rgb),0.15); color: var(--accent); font-weight: 600; border: 1px solid var(--accent-dark); }
.table-wrap::-webkit-scrollbar { width: 6px; height: 6px; }
.table-wrap::-webkit-scrollbar-thumb { background: var(--accent-dark); border-radius: 3px; }

/* === TRIGONOMETRIE === */
.trig-q{background:linear-gradient(90deg,var(--accent-dark),#004d18);color:#000;text-align:center;padding:7px 10px;border-radius:6px 6px 0 0;font-weight:800;font-size:0.82rem;margin-top:12px;letter-spacing:0.5px}
.trig-scroll{overflow-x:auto;border:1px solid var(--border);border-top:none;border-radius:0 0 6px 6px;background:var(--input-bg);margin-bottom:15px}
.trig-t{border-collapse:collapse;font-size:0.76rem;white-space:nowrap;width:100%}
.trig-t td{border:1px solid var(--border);padding:4px 6px;text-align:center;min-width:62px}
.tl{background:rgba(var(--accent-rgb),0.08)!important;font-weight:bold;color:var(--accent)!important;text-align:left!important;padding-left:6px!important;min-width:48px!important;max-width:48px;position:sticky;left:0;z-index:1}
.r-deg{background:rgba(255,248,225,0.03)}.r-rpi{background:rgba(243,229,245,0.03)}.r-rdec{background:rgba(232,245,233,0.03)}
.r-sin{background:rgba(252,228,236,0.03)}.r-cos{background:rgba(227,242,253,0.03)}.r-tan{background:rgba(255,243,224,0.03)}
.neg{color:#ff6b6b}

/* === CARDELE FORMULE === */
.fcards{display:grid;gap:10px;margin-top:10px}
.fcard{background:var(--hover-bg);border:1px solid var(--border);border-radius:6px;overflow:hidden}
.fhead{background:rgba(var(--accent-rgb),0.08);color:var(--accent);font-weight:bold;padding:6px 12px;font-size:0.82rem;border-bottom:1px solid var(--accent-dark)}
.fbody{padding:8px 12px}
.fline{display:flex;align-items:center;padding:5px 0;border-bottom:1px dashed var(--border);font-size:0.88rem;gap:6px;flex-wrap:wrap}
.fline:last-child{border-bottom:none}

/* === RESPONSIVE UNIFICAT === */
@media (max-width: 700px) {
  .m-tab { flex: 1 1 calc(50% - 8px); }
}
@media (max-width: 500px) {
  .header-row { flex-direction: column; gap: 8px; }
  .header-ext-row { gap: 8px; }
  .ext-btn { flex: 1 1 calc(50% - 5px); max-width: none; justify-content: center; }
  .m-tab { flex: 1 1 100%; max-width: 100%; padding: 10px 0; font-size: 0.8rem; }
  .main-tabs, .sub-tabs { gap: 6px; }
}
[data-theme="carbon"] {
  --bg: #0d1117; --card-bg: #161b22; --text: #e6edf3; --text-muted: #8b949e;
  --accent: #58a6ff; --accent-dark: #1f6feb; --accent-glow: rgba(88,166,255,0.18);
  --accent-rgb: 88,166,255;
  --border: #30363d; --input-bg: #0d1117; --input-border: #30363d; --hover-bg: #21262d;
}
[data-theme="sepia"] {
  --bg: #ffffff; --card-bg: #ffffff; --text: #1f2328; --text-muted: #59636e;
  --accent: #4b5563; --accent-dark: #6b7280; --accent-glow: rgba(31,35,40,0.08);
  --accent-rgb: 75,85,99;
  --border: #d0d7de; --input-bg: #f6f8fa; --input-border: #d0d7de; --hover-bg: #f6f8fa;
}
[data-theme="sepia"] body {
  background-image: none;
}
[data-theme="sepia"] .container {
  box-shadow: none;
}
[data-theme="sepia"] .m-tab,
[data-theme="sepia"] .s-tab,
[data-theme="sepia"] .lang-link,
[data-theme="sepia"] .ext-btn,
[data-theme="sepia"] #theme-toggle {
  color: #000000 !important;
}
[data-theme="sepia"] .m-tab,
[data-theme="sepia"] .s-tab,
[data-theme="sepia"] .ext-btn {
  background: #f6f8fa;
  border-color: #b6bec8;
}
[data-theme="sepia"] .m-tab:hover,
[data-theme="sepia"] .s-tab:hover,
[data-theme="sepia"] .lang-link:hover,
[data-theme="sepia"] .ext-btn:hover,
[data-theme="sepia"] #theme-toggle:hover {
  color: #000000 !important;
  background: #eaeef2;
}
[data-theme="sepia"] .m-tab.active,
[data-theme="sepia"] .lang-link.active,
[data-theme="sepia"] .s-tab.active {
  color: #ffffff !important;
  background: #4b5563;
  border-color: #374151;
}
[data-theme="sepia"] button,
[data-theme="sepia"] .theme-toggle-btn:hover {
  color: #ffffff !important;
}
#theme-toggle {
  background: transparent; border: 1px solid var(--border); color: var(--text-muted);
  padding: 4px 8px; border-radius: 4px; cursor: pointer; font-size: 1.2rem;
  transition: 0.2s; margin-left: 8px;
}
#theme-toggle:hover { background: var(--hover-bg); color: var(--accent); }

@media print {
  :root {
    --bg: #ffffff; --card-bg: #ffffff; --text: #000000; --text-muted: #444444;
    --accent: #000000; --accent-dark: #777777; --accent-glow: transparent;
    --accent-rgb: 0,0,0;
    --border: #bbbbbb; --input-bg: #ffffff; --input-border: #999999; --hover-bg: #f2f2f2;
  }
  body {
    background: #ffffff !important;
    background-image: none !important;
    color: #000000 !important;
    padding: 0;
  }
  .container {
    box-shadow: none !important;
    border: none;
    max-width: none;
  }
  button, .lang-switch, .header-ext-row {
    display: none !important;
  }
}