body { font-family: 'Nunito', sans-serif; text-align: center; padding: 30px 20px; background: linear-gradient(135deg, #f0f4f8 0%, #e0e7ff 100%); color: #1e293b; min-height: 100vh; }
h1 { margin-bottom: 30px; }
.card { background: white; padding: 30px 20px; border-radius: 24px; box-shadow: 0 10px 30px rgba(99, 102, 241, 0.1); max-width: 400px; margin: 0 auto 30px auto; transition: transform 0.3s ease; border: 1px solid rgba(255,255,255,0.5); }
.card:hover { transform: translateY(-5px); }
.btn { display: block; padding: 15px; margin-top: 15px; font-size: 18px; color: white; background: linear-gradient(135deg, #6366f1, #8b5cf6); text-decoration: none; border-radius: 14px; font-weight: 700; transition: all 0.3s ease; box-shadow: 0 4px 15px rgba(99, 102, 241, 0.3); border: none; }
.btn:hover { transform: translateY(-3px); box-shadow: 0 8px 25px rgba(99, 102, 241, 0.5); filter: brightness(1.1); }
.btn-admin { background-color: #6c757d; font-size: 14px; padding: 10px; margin-top: 40px; }
.btn-admin:hover { background-color: #5a6268; box-shadow: none; transform: none; }

/* --- Hilfe-Modal --- */
.modal { display: none; position: fixed; z-index: 1001; left: 0; top: 0; width: 100%; height: 100%; overflow: auto; background-color: rgba(0,0,0,0.6); }
.modal-content { background-color: #fefefe; margin: 15% auto; padding: 25px; border: 1px solid #888; width: 80%; max-width: 500px; border-radius: 10px; position: relative; }
.close-btn { color: #aaa; position: absolute; top: 10px; right: 25px; font-size: 35px; font-weight: bold; cursor: pointer; }
.help-link { font-size: 14px; color: #6366f1; text-decoration: underline; cursor: pointer; margin-top: 15px; display: inline-block; font-weight: 600; }

/* --- Ausgelagerte Inline-Styles --- */
.lang-selector-container { display: flex; justify-content: flex-end; padding: 10px; max-width: 800px; margin: 0 auto; }
.lang-select { background: white; border: 2px solid #e2e8f0; border-radius: 12px; padding: 8px 12px; font-family: inherit; font-size: 16px; cursor: pointer; box-shadow: 0 4px 10px rgba(0,0,0,0.05); outline: none; font-weight: 700; color: #475569; }
.btn-large { width: 100%; border: none; cursor: pointer; font-size: 22px; }
.btn-full { width: 100%; border: none; cursor: pointer; margin: 0; }
.find-rooms-link { font-size: 12px; color: #6c757d; margin-top: 10px; display: block; cursor: pointer; }
.page-footer { margin-top: 50px; font-size: 12px; color: #6c757d; }
.page-footer a { color: inherit; margin: 0 10px; }
.modal-title { color: #6366f1; margin-top: 0; }
.modal-title.danger { color: #ef4444; }
.tts-btn { background: none; border: none; font-size: 24px; cursor: pointer; padding: 0; box-shadow: none; vertical-align: middle; }
.warning-text { color: #ef4444; font-size: 14px; font-weight: bold; margin-top: 15px; }
.warning-text-margin { margin-bottom: 20px; }
.modal-hr { border: 0; border-top: 1px solid #eee; margin: 15px 0; }
.probemodus-text { font-size: 14px; color: #64748b; }
.modal-content-centered { text-align: center; padding: 30px; }
.modal-text { font-size: 16px; }
.form-input { width: 100%; padding: 15px; margin: 15px 0; font-size: 18px; border-radius: 12px; border: 2px solid #cbd5e1; outline: none; font-family: inherit; box-sizing: border-box; }
.teacher-key-display { font-size: 28px; font-weight: 800; background: #fee2e2; padding: 15px; border-radius: 12px; margin: 15px 0; color: #b91c1c; border: 2px dashed #f87171; }
.room-id-display { font-size: 48px; font-weight: 900; letter-spacing: 6px; color: #0f172a; margin: 15px 0; }
.qr-container { display: flex; justify-content: space-around; flex-wrap: wrap; margin-top: 25px; margin-bottom: 25px; }
.qr-title { font-size: 18px; font-weight: bold; color: #64748b; margin-bottom: 10px; margin-top: 0; }
.qr-img { width: 140px; height: 140px; border-radius: 12px; box-shadow: 0 8px 20px rgba(0,0,0,0.1); cursor: zoom-in; }
.modal-transparent { text-align: center; background: transparent; border: none; box-shadow: none; margin-top: 10%; padding: 0; }
.close-btn-outside { color: white; top: -40px; right: 20px; }
.qr-modal-img { width: 100%; max-width: 500px; border-radius: 16px; background: white; padding: 20px; box-sizing: border-box; box-shadow: 0 10px 40px rgba(0,0,0,0.5); }
.qr-modal-text { color: white; font-weight: bold; font-size: 18px; margin-top: 15px; text-shadow: 0 2px 4px rgba(0,0,0,0.5); }
.mt-20 { margin-top: 20px; }