:root {
    --primary: #4834d4;
    --accent: #eb4d4b;
    --bg-body: #f8f9fa;
}

body { font-family: 'Montserrat', sans-serif; background-color: var(--bg-body); margin: 0; color: #2d3436; overflow-x: hidden; }

header { 
    background: linear-gradient(135deg, #1e3799, #4834d4); 
    color: white; padding: 3rem 1rem 6rem; text-align: center; 
    clip-path: polygon(0 0, 100% 0, 100% 85%, 0% 100%); 
    position: relative; z-index: 1;
}

h1 { font-size: 3.5rem; margin: 0; font-weight: 900; letter-spacing: -2px; }

.container { max-width: 800px; margin: -70px auto 40px; padding: 0 20px; position: relative; z-index: 10; }

.instrument-tabs { display: flex; justify-content: center; gap: 15px; margin-bottom: 25px; }

.tab-btn { 
    border: none; padding: 15px 30px; border-radius: 20px; font-weight: 700; 
    cursor: pointer; transition: 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275); 
    background: white; box-shadow: 0 10px 20px rgba(0,0,0,0.1); color: #666; 
}

.tab-btn.active { background: var(--accent); color: white; transform: scale(1.1) translateY(-5px); }

/* TUNER BOX & TEMALAR */
.tuner-box { 
    border-radius: 40px; padding: 50px; position: relative; 
    transition: all 0.6s ease; overflow: hidden;
    box-shadow: 0 30px 60px rgba(0,0,0,0.15);
}

/* Gitar: Sıcak Ahşap ve Gün Batımı */
.gitar-theme { background: linear-gradient(45deg, #8e44ad, #d35400); }
/* Ukulele: Deniz ve Güneş */
.ukulele-theme { background: linear-gradient(45deg, #00cec9, #fdcb6e); }
/* Bağlama: Toprak ve Bakır */
.baglama-theme { background: linear-gradient(45deg, #2c3e50, #27ae60); }

.content-overlay { position: relative; z-index: 2; color: white; }

.string-grid { display: flex; flex-direction: column-reverse; gap: 12px; margin: 30px 0; }

/* Butonlarda Cam Efekti (Glassmorphism) */
.string-btn { 
    width: 100%; padding: 22px; border: 1px solid rgba(255,255,255,0.3); 
    border-radius: 20px; background: rgba(255,255,255,0.15); 
    backdrop-filter: blur(10px); color: white; cursor: pointer; 
    transition: 0.3s; display: flex; justify-content: space-between; align-items: center;
    font-weight: 700; font-size: 1.1rem;
}

.string-btn:hover { background: rgba(255,255,255,0.3); transform: scale(1.02); }
.string-btn.playing { background: white; color: #2d3436; box-shadow: 0 0 30px rgba(255,255,255,0.6); }

.btn-stop { 
    background: rgba(0,0,0,0.4); color: white; border: 1px solid rgba(255,255,255,0.2); 
    padding: 15px 45px; border-radius: 50px; font-weight: 700; cursor: pointer;
    transition: 0.3s;
}
.btn-stop:hover { background: #000; }

footer { text-align: center; padding: 50px; margin-top: 50px; background: white; }
footer a { color: var(--primary); text-decoration: none; font-weight: 900; font-size: 1.3rem; }