:root {
    --primary-blue: #0F4C81;
    --steel-grey: #F5F7FA;
    --text-dark: #2C3E50;
    --accent-blue: #4A90E2;
    --alert-red: #E74C3C;
    --success-green: #2ECC71;
    --transition: all 0.4s cubic-bezier(0.25, 0.8, 0.25, 1);
}

* { box-sizing: border-box; margin: 0; padding: 0; font-family: 'Segoe UI', system-ui, sans-serif; }

body { background-color: var(--steel-grey); color: var(--text-dark); display: flex; justify-content: center; align-items: center; min-height: 100vh; }

.app-container { width: 100%; max-width: 800px; background: white; border-radius: 12px; box-shadow: 0 10px 30px rgba(0,0,0,0.08); overflow: hidden; position: relative; min-height: 600px; }

.screen { display: none; padding: 40px; opacity: 0; transform: translateY(20px); transition: var(--transition); }
.screen.active { display: block; opacity: 1; transform: translateY(0); }

/* Typography & Buttons */
h1, h2 { color: var(--primary-blue); margin-bottom: 20px; text-align: center; }
p { line-height: 1.6; margin-bottom: 20px; text-align: center; }

.btn-primary, .btn-secondary { display: block; width: 100%; max-width: 300px; margin: 0 auto; padding: 15px; border: none; border-radius: 8px; font-size: 1.1rem; font-weight: bold; cursor: pointer; transition: var(--transition); }
.btn-primary { background: var(--primary-blue); color: white; }
.btn-primary:hover { background: var(--accent-blue); transform: translateY(-2px); }
.btn-secondary { background: transparent; border: 2px solid var(--primary-blue); color: var(--primary-blue); margin-top: 20px; }

/* Test Header & Chronograph */
.test-header { display: flex; justify-content: space-between; align-items: center; margin-bottom: 30px; border-bottom: 2px solid var(--steel-grey); padding-bottom: 20px; }
.progress-container { flex: 1; height: 8px; background: var(--steel-grey); border-radius: 4px; margin-right: 20px; overflow: hidden; }
.progress-bar { height: 100%; background: var(--primary-blue); width: 0%; transition: width 0.5s ease; }

.chronograph-wrapper { position: relative; width: 60px; height: 60px; }
.circular-timer { transform: rotate(-90deg); width: 100%; height: 100%; }
.timer-bg { fill: none; stroke: var(--steel-grey); stroke-width: 8; }
.timer-path { fill: none; stroke: var(--accent-blue); stroke-width: 8; stroke-dasharray: 283; stroke-dashoffset: 0; transition: stroke-dashoffset 1s linear; }
.timer-text { position: absolute; top: 50%; left: 50%; transform: translate(-50%, -50%); font-weight: bold; font-size: 1.2rem; }
.domain-badge { background: var(--steel-grey); padding: 5px 15px; border-radius: 20px; font-size: 0.9rem; font-weight: bold; color: var(--primary-blue); }

/* Questions */
.question-title { font-size: 1.4rem; margin-bottom: 20px; text-align: center; }
.visual-area { background: var(--steel-grey); min-height: 200px; border-radius: 8px; display: flex; justify-content: center; align-items: center; margin-bottom: 30px; font-size: 2rem; letter-spacing: 5px; }
.options-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(150px, 1fr)); gap: 15px; }
.option-btn { padding: 15px; border: 2px solid var(--steel-grey); border-radius: 8px; background: white; cursor: pointer; font-size: 1.1rem; transition: var(--transition); }
.option-btn:hover { border-color: var(--accent-blue); background: var(--steel-grey); }

/* Processing & Results */
.loader { border: 6px solid var(--steel-grey); border-top: 6px solid var(--primary-blue); border-radius: 50%; width: 60px; height: 60px; animation: spin 1s linear infinite; margin: 0 auto 20px; }
@keyframes spin { 0% { transform: rotate(0deg); } 100% { transform: rotate(360deg); } }

.results-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 30px; margin-top: 30px; }
.iq-score-display { text-align: center; background: var(--primary-blue); color: white; padding: 30px; border-radius: 12px; margin-bottom: 30px; }
.iq-number { font-size: 4rem; font-weight: bold; margin: 10px 0; }
.stats-list { list-style: none; }
.stats-list li { padding: 10px 0; border-bottom: 1px solid var(--steel-grey); display: flex; justify-content: space-between; }

@media (max-width: 600px) { .results-grid { grid-template-columns: 1fr; } }