/**
 * ===== 안심케어 랜딩 페이지 CSS =====
 * 파일명: landing.css
 * 목적: 노인 친화적 랜딩 페이지 디자인
 *
 * 🎨 노인 친화적 디자인 원칙:
 * - 큰 글자: 최소 18px, 제목 24px+
 * - 높은 대비: 명확한 색상 구분
 * - 넉넉한 터치: 버튼 최소 48px 높이
 * - 명확한 구분: 충분한 여백과 구분선
 */

/* =====================================
   전역 스타일
   ===================================== */

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Malgun Gothic', 'Apple SD Gothic Neo', sans-serif;
    font-size: 18px;
    line-height: 1.7;
    color: #333;
    background: #f8f9fa;
}

.container {
    max-width: 680px;
    margin: 0 auto;
    padding: 0 20px;
}

/* =====================================
   헤더
   ===================================== */

.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px 0;
    text-align: center;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 12px;
    margin-bottom: 10px;
}

.logo-icon {
    font-size: 48px;
}

.logo-text {
    font-size: 36px;
    font-weight: 900;
}

.tagline {
    font-size: 18px;
    opacity: 0.95;
    font-weight: 500;
}

/* =====================================
   메인 콘텐츠
   ===================================== */

.main {
    padding: 40px 0;
}

section {
    margin-bottom: 50px;
}

.section-title {
    font-size: 28px;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 20px;
    text-align: center;
}

/* =====================================
   앱 소개 섹션
   ===================================== */

.intro-section {
    text-align: center;
    padding: 30px 20px;
    background: white;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.app-icon-large {
    margin-bottom: 20px;
}

.app-icon-large .icon {
    font-size: 80px;
}

.intro-title {
    font-size: 32px;
    font-weight: 900;
    color: #1e293b;
    margin-bottom: 20px;
    line-height: 1.4;
}

.intro-desc {
    font-size: 18px;
    color: #475569;
    line-height: 1.8;
}

/* =====================================
   다운로드 섹션
   ===================================== */

.download-section {
    background: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.download-btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    width: 100%;
    padding: 20px 30px;
    margin: 15px 0;
    font-size: 20px;
    font-weight: 700;
    text-decoration: none;
    border-radius: 12px;
    min-height: 70px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.download-btn:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.download-btn:active {
    transform: translateY(0);
}

.android-btn {
    background: linear-gradient(135deg, #3DDC84 0%, #2BB968 100%);
    color: white;
}

.ios-btn {
    background: linear-gradient(135deg, #000000 0%, #2c2c2c 100%);
    color: white;
}

.btn-icon {
    font-size: 32px;
}

.btn-text {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 4px;
}

.btn-text strong {
    font-size: 24px;
}

.btn-text small {
    font-size: 14px;
    font-weight: 400;
    opacity: 0.9;
}

.download-note {
    margin-top: 20px;
    padding: 15px;
    background: #fff3cd;
    border: 2px solid #ffc107;
    border-radius: 8px;
    font-size: 15px;
    color: #856404;
}

.download-note p {
    margin: 5px 0;
}

/* =====================================
   초대코드 섹션
   ===================================== */

.invite-section {
    background: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.invite-card {
    text-align: center;
}

.invite-desc {
    font-size: 16px;
    color: #64748b;
    margin-bottom: 25px;
    line-height: 1.7;
}

.invite-code-display {
    display: flex;
    gap: 12px;
    margin: 25px 0;
}

.code-box {
    flex: 1;
    background: linear-gradient(135deg, #f0f8ff 0%, #e6f3ff 100%);
    border: 3px solid #74c0fc;
    border-radius: 12px;
    padding: 20px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.code-text {
    font-size: 36px;
    font-weight: 900;
    letter-spacing: 8px;
    color: #1e40af;
    font-family: 'Courier New', monospace;
}

.copy-btn {
    padding: 20px 30px;
    font-size: 20px;
    font-weight: 700;
    background: #FEE500;
    color: #000;
    border: none;
    border-radius: 12px;
    cursor: pointer;
    min-width: 120px;
    min-height: 60px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.copy-btn:hover {
    background: #FFD700;
    transform: scale(1.05);
}

.copy-btn:active {
    transform: scale(0.98);
}

.invite-note {
    font-size: 15px;
    color: #dc3545;
    background: #f8d7da;
    border: 2px solid #f5c2c7;
    border-radius: 8px;
    padding: 15px;
    margin-top: 20px;
}

/* =====================================
   주요 기능 섹션
   ===================================== */

.features-section {
    background: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 20px;
    margin-top: 25px;
}

.feature-card {
    background: #f8f9fa;
    border: 2px solid #e9ecef;
    border-radius: 12px;
    padding: 25px;
    text-align: center;
    transition: all 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
    border-color: #667eea;
}

.feature-icon {
    font-size: 48px;
    margin-bottom: 15px;
}

.feature-title {
    font-size: 20px;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 12px;
}

.feature-desc {
    font-size: 16px;
    color: #64748b;
    line-height: 1.6;
}

/* =====================================
   사용 방법 섹션
   ===================================== */

.howto-section {
    background: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.howto-steps {
    margin-top: 25px;
}

.step {
    display: flex;
    gap: 20px;
    margin-bottom: 30px;
    align-items: flex-start;
}

.step:last-child {
    margin-bottom: 0;
}

.step-number {
    flex-shrink: 0;
    width: 50px;
    height: 50px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    font-weight: 900;
}

.step-content h3 {
    font-size: 20px;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 8px;
}

.step-content p {
    font-size: 16px;
    color: #64748b;
    line-height: 1.6;
}

/* =====================================
   광고 섹션
   ===================================== */

.banner-inquiry-section {
    background: white;
    padding: 30px;
    border-radius: 16px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
}

.banner-subtitle {
    text-align: center;
    font-size: 16px;
    color: #64748b;
    margin-bottom: 30px;
}

.banner-card {
    display: flex;
    gap: 20px;
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    border: 2px solid #dee2e6;
    border-radius: 12px;
    padding: 25px;
    margin-bottom: 20px;
    transition: all 0.3s ease;
}

.banner-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.1);
    border-color: #667eea;
}

.banner-icon {
    flex-shrink: 0;
    font-size: 48px;
    width: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.banner-content {
    flex: 1;
}

.banner-title {
    font-size: 22px;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 10px;
}

.banner-desc {
    font-size: 16px;
    color: #64748b;
    line-height: 1.6;
    margin-bottom: 15px;
}

.banner-desc strong {
    color: #667eea;
}

.banner-btn {
    display: inline-block;
    padding: 12px 24px;
    font-size: 18px;
    font-weight: 700;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-decoration: none;
    border-radius: 8px;
    transition: all 0.3s ease;
}

.banner-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

.banner-info-box {
    background: linear-gradient(135deg, #e8f5e9 0%, #c8e6c9 100%);
    border: 2px solid #4caf50;
    border-radius: 12px;
    padding: 25px;
    margin-top: 30px;
}

.banner-info-box h3 {
    font-size: 22px;
    font-weight: 700;
    color: #1e293b;
    margin-bottom: 15px;
}

.banner-info-box ul {
    list-style: none;
    padding: 0;
    margin: 0 0 20px 0;
}

.banner-info-box li {
    font-size: 16px;
    color: #2e7d32;
    margin-bottom: 10px;
    padding-left: 0;
}

.banner-info-contact {
    font-size: 18px;
    font-weight: 600;
    color: #1e293b;
    margin-top: 20px;
    padding-top: 20px;
    border-top: 2px solid #4caf50;
    line-height: 1.8;
}

.banner-info-contact a {
    color: #667eea;
    text-decoration: none;
    font-weight: 700;
}

.banner-info-contact a:hover {
    text-decoration: underline;
}

.banner-disclaimer {
    font-size: 14px;
    color: #6c757d;
    text-align: center;
    margin-top: 25px;
    padding: 15px;
    background: #fff3cd;
    border-radius: 8px;
    border: 1px solid #ffc107;
}

/* =====================================
   푸터
   ===================================== */

.footer {
    background: #1e293b;
    color: #cbd5e1;
    padding: 40px 0 30px;
    margin-top: 50px;
}

.footer-content {
    text-align: center;
}

.footer-brand {
    font-size: 24px;
    font-weight: 900;
    color: white;
    margin-bottom: 10px;
}

.footer-desc {
    font-size: 16px;
    margin-bottom: 25px;
    opacity: 0.8;
}

.footer-links {
    margin-bottom: 25px;
    font-size: 15px;
}

.footer-links a {
    color: #94a3b8;
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: white;
}

.footer-links .separator {
    margin: 0 10px;
    color: #475569;
}

.footer-info {
    font-size: 14px;
    color: #94a3b8;
    margin-bottom: 20px;
    line-height: 1.8;
}

.footer-info p {
    margin: 5px 0;
}

.footer-copyright {
    font-size: 14px;
    color: #64748b;
    padding-top: 20px;
    border-top: 1px solid #334155;
}

/* =====================================
   반응형 디자인
   ===================================== */

@media (max-width: 768px) {
    body {
        font-size: 17px;
    }

    .logo-text {
        font-size: 32px;
    }

    .tagline {
        font-size: 16px;
    }

    .intro-title {
        font-size: 28px;
    }

    .section-title {
        font-size: 24px;
    }

    .download-btn {
        padding: 18px 25px;
        min-height: 65px;
    }

    .btn-text strong {
        font-size: 22px;
    }

    .code-text {
        font-size: 28px;
        letter-spacing: 5px;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

    .banner-card {
        flex-direction: column;
        text-align: center;
    }

    .banner-icon {
        width: 100%;
    }
}

@media (max-width: 480px) {
    body {
        font-size: 16px;
    }

    .container {
        padding: 0 15px;
    }

    .logo-icon {
        font-size: 40px;
    }

    .logo-text {
        font-size: 28px;
    }

    .intro-title {
        font-size: 24px;
    }

    .section-title {
        font-size: 22px;
    }

    .invite-code-display {
        flex-direction: column;
    }

    .copy-btn {
        width: 100%;
    }

    .code-text {
        font-size: 24px;
        letter-spacing: 4px;
    }
}

/* =====================================
   접근성 개선
   ===================================== */

/* 포커스 표시 강화 */
button:focus,
a:focus {
    outline: 3px solid #667eea;
    outline-offset: 2px;
}

/* 터치 영역 확대 */
button,
a.download-btn,
a.banner-btn {
    min-height: 48px;
    touch-action: manipulation;
}

/* 고대비 모드 지원 */
@media (prefers-contrast: high) {
    .feature-card,
    .banner-card {
        border-width: 3px;
    }

    button,
    .download-btn,
    .banner-btn {
        border: 2px solid currentColor;
    }
}

/* 애니메이션 감소 설정 존중 */
@media (prefers-reduced-motion: reduce) {
    * {
        animation: none !important;
        transition: none !important;
    }
}