:root {
    --bg: #0f172a; --card: #1e293b; --text: #f1f5f9; --accent: #38bdf8; --border: #334155; --font: 'Inter', sans-serif;
}

[data-theme="light"] {
    --bg: #f8fafc; --card: #ffffff; --text: #0f172a; --accent: #2563eb; --border: #e2e8f0;
}

[data-theme="synthwave"] {
    --bg: #2b065a; --card: #1a0633; --text: #3fffd2; --accent: #ff00ff; --border: #ff00ff;
}

[data-theme="matrix"] {
    --bg: #000000; --card: #000000; --text: #00ff41; --accent: #008f11; --border: #00ff41; --font: 'Fira Code', monospace;
}

[data-theme="dracula"] {
    --bg: #282a36; --card: #44475a; --text: #f8f8f2; --accent: #bd93f9; --border: #6272a4;
}

* { box-sizing: border-box; margin: 0; padding: 0; -webkit-tap-highlight-color: transparent; }

body {
    background-color: var(--bg);
    color: var(--text);
    font-family: var(--font);
    transition: all 0.3s ease;
    line-height: 1.5;
}

header {
    background: rgba(0,0,0,0.2);
    padding: 15px;
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
}

.header-top { display: flex; justify-content: space-between; align-items: center; margin-bottom: 15px; }
h1 { font-size: 1.5rem; font-weight: 800; letter-spacing: -1px; }
h1 span { color: var(--accent); }

#theme-select {
    background: var(--card); color: var(--text); border: 1px solid var(--border); padding: 5px; border-radius: 5px;
}

.search-bar input {
    width: 100%; padding: 12px; border-radius: 10px; border: 1px solid var(--border);
    background: var(--card); color: var(--text); font-size: 1rem;
}

.filter-nav { display: flex; overflow-x: auto; gap: 8px; margin-top: 15px; padding-bottom: 5px; }
.filter-btn {
    white-space: nowrap; background: transparent; border: 1px solid var(--accent);
    color: var(--text); padding: 6px 12px; border-radius: 15px; font-size: 0.8rem; cursor: pointer;
}
.filter-btn.active { background: var(--accent); color: #000; font-weight: 600; }

.substance-grid {
    display: grid; grid-template-columns: repeat(auto-fill, minmax(140px, 1fr));
    gap: 12px; padding: 15px;
}

.card {
    background: var(--card); border: 1px solid var(--border); padding: 15px;
    border-radius: 12px; transition: transform 0.1s; cursor: pointer;
}
.card:active { transform: scale(0.96); }
.card h3 { font-size: 0.9rem; margin-bottom: 5px; color: var(--accent); }
.card p { font-size: 0.7rem; opacity: 0.8; }

/* Modal */
.modal {
    display: none; position: fixed; z-index: 2000; left: 0; top: 0; width: 100%; height: 100%;
    background: rgba(0,0,0,0.8); backdrop-filter: blur(4px);
}
.modal-content {
    background: var(--bg); margin: 10% auto; padding: 25px; width: 90%; max-width: 500px;
    border-radius: 20px; border: 1px solid var(--accent); max-height: 80vh; overflow-y: auto;
}
.close-modal { float: right; font-size: 28px; font-weight: bold; cursor: pointer; }

.dose-table { display: flex; justify-content: space-between; margin: 20px 0; gap: 10px; }
.dose-unit { flex: 1; background: var(--card); padding: 10px; border-radius: 8px; text-align: center; border-bottom: 3px solid var(--accent); }
.dose-unit label { display: block; font-size: 0.7rem; text-transform: uppercase; opacity: 0.6; }

.info-box { margin-bottom: 15px; }
.info-box h4 { font-size: 0.8rem; color: var(--accent); text-transform: uppercase; margin-bottom: 4px; }
.info-box p { font-size: 0.9rem; opacity: 0.9; }

@media (max-width: 350px) { .substance-grid { grid-template-columns: 1fr 1fr; } }