/* ==========================================================================
   SecureShare - スタイルシート
   セキュリティとプライバシーを意識したモダン＆洗練されたUIデザイン
   ========================================================================== */

:root {
  /* カラーパレット */
  --bg-primary: #0a0f1d;
  --bg-secondary: #131b2e;
  --bg-card: rgba(19, 27, 46, 0.75);
  --bg-card-hover: rgba(28, 38, 64, 0.85);
  --border-color: rgba(255, 255, 255, 0.08);
  --border-focus: #10b981;

  --text-main: #f1f5f9;
  --text-muted: #94a3b8;
  --text-dim: #64748b;

  --accent-primary: #10b981;       /* エメラルドグリーン（安全・信頼） */
  --accent-primary-hover: #059669;
  --accent-cyan: #06b6d4;          /* シアン（暗号技術・先進性） */
  --accent-danger: #ef4444;        /* 破棄・警告 */
  --accent-warning: #f59e0b;       /* ワンタイム警告 */

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.25);
  --shadow-glow: 0 0 25px rgba(16, 185, 129, 0.15);
  --radius-sm: 6px;
  --radius-md: 12px;
  --radius-lg: 18px;

  --transition-fast: 0.2s ease;
  --transition-smooth: 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

/* リセット＆ベーススタイル */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  line-height: 1.6;
  background-image: 
    radial-gradient(circle at 15% 20%, rgba(16, 185, 129, 0.06) 0%, transparent 40%),
    radial-gradient(circle at 85% 75%, rgba(6, 182, 212, 0.06) 0%, transparent 40%);
  background-attachment: fixed;
}

/* ヘッダー */
.header {
  padding: 1.5rem 2rem;
  border-bottom: 1px solid var(--border-color);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  position: sticky;
  top: 0;
  z-index: 50;
}

.header-container {
  max-width: 860px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-decoration: none;
  color: var(--text-main);
  font-weight: 700;
  font-size: 1.25rem;
  letter-spacing: -0.02em;
}

.logo-icon {
  width: 28px;
  height: 28px;
  color: var(--accent-primary);
}

.badge-tag {
  font-size: 0.75rem;
  padding: 0.2rem 0.6rem;
  border-radius: 999px;
  background: rgba(16, 185, 129, 0.12);
  color: var(--accent-primary);
  border: 1px solid rgba(16, 185, 129, 0.25);
  font-weight: 600;
}

/* メインコンテナ */
.main-content {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2.5rem 1rem;
}

.card {
  width: 100%;
  max-width: 600px;
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2rem;
  box-shadow: var(--shadow-sm), var(--shadow-glow);
  position: relative;
  transition: transform var(--transition-smooth);
}

.card-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 0.5rem;
  letter-spacing: -0.02em;
}

.card-desc {
  font-size: 0.9rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
}

/* ゼロナレッジバナー */
.security-banner {
  background: rgba(6, 182, 212, 0.08);
  border: 1px solid rgba(6, 182, 212, 0.2);
  border-radius: var(--radius-md);
  padding: 0.85rem 1rem;
  margin-bottom: 1.5rem;
  display: flex;
  align-items: flex-start;
  gap: 0.75rem;
  font-size: 0.825rem;
  color: #a5f3fc;
}

.security-banner-icon {
  flex-shrink: 0;
  width: 18px;
  height: 18px;
  margin-top: 2px;
}

/* タブ切り替え */
.tabs {
  display: flex;
  gap: 0.5rem;
  background: rgba(0, 0, 0, 0.25);
  padding: 0.3rem;
  border-radius: var(--radius-md);
  margin-bottom: 1.25rem;
}

.tab-btn {
  flex: 1;
  background: transparent;
  border: none;
  padding: 0.6rem;
  color: var(--text-muted);
  font-size: 0.875rem;
  font-weight: 600;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.tab-btn.active {
  background: var(--bg-secondary);
  color: var(--text-main);
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.4);
}

/* フォーム要素 */
.form-group {
  margin-bottom: 1.25rem;
}

.form-label {
  display: block;
  font-size: 0.825rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.4rem;
}

.form-input, .form-textarea, .form-select {
  width: 100%;
  background: rgba(10, 15, 29, 0.65);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 0.75rem 1rem;
  color: var(--text-main);
  font-size: 0.95rem;
  transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
  outline: none;
}

.form-textarea {
  min-height: 130px;
  resize: vertical;
  font-family: inherit;
}

.form-input:focus, .form-textarea:focus, .form-select:focus {
  border-color: var(--border-focus);
  box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.2);
}

/* ボタン群 */
.btn-primary {
  width: 100%;
  background: linear-gradient(135deg, var(--accent-primary), #059669);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  padding: 0.85rem 1.25rem;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.5rem;
  transition: transform var(--transition-fast), filter var(--transition-fast), box-shadow var(--transition-fast);
  box-shadow: 0 4px 14px rgba(16, 185, 129, 0.3);
}

.btn-primary:hover {
  filter: brightness(1.08);
  transform: translateY(-1px);
  box-shadow: 0 6px 20px rgba(16, 185, 129, 0.4);
}

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

.btn-primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  border-radius: var(--radius-md);
  padding: 0.65rem 1rem;
  font-size: 0.875rem;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  transition: background var(--transition-fast);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 0.12);
}

.btn-danger {
  background: linear-gradient(135deg, var(--accent-danger), #b91c1c);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  padding: 0.85rem 1.25rem;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  width: 100%;
  box-shadow: 0 4px 14px rgba(239, 68, 68, 0.3);
}

.btn-danger:hover {
  filter: brightness(1.08);
}

/* 発行結果カード */
.result-box {
  background: rgba(0, 0, 0, 0.3);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin-top: 1.5rem;
}

.url-display {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.6rem;
}

.url-input {
  flex: 1;
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 0.6rem 0.8rem;
  color: #38bdf8;
  font-family: monospace;
  font-size: 0.85rem;
  outline: none;
}

/* 閲覧確認用ウォーニング */
.warning-box {
  background: rgba(245, 158, 11, 0.1);
  border: 1px solid rgba(245, 158, 11, 0.3);
  border-radius: var(--radius-md);
  padding: 1.2rem;
  margin-bottom: 1.5rem;
  color: #fde68a;
}

.warning-title {
  font-weight: 700;
  font-size: 1rem;
  margin-bottom: 0.3rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

/* シークレット表示領域 */
.secret-display-area {
  background: rgba(0, 0, 0, 0.4);
  border: 1px solid rgba(16, 185, 129, 0.3);
  border-radius: var(--radius-md);
  padding: 1.25rem;
  margin: 1.5rem 0;
  position: relative;
}

.secret-text {
  font-family: monospace;
  font-size: 1.1rem;
  white-space: pre-wrap;
  word-break: break-all;
  color: #ecfdf5;
}

/* トースト通知 */
.toast {
  position: fixed;
  bottom: 2rem;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--bg-secondary);
  border: 1px solid var(--accent-primary);
  color: var(--text-main);
  padding: 0.75rem 1.5rem;
  border-radius: 999px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
  font-size: 0.875rem;
  opacity: 0;
  pointer-events: none;
  transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  z-index: 100;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* フッター */
.footer {
  padding: 1.5rem;
  text-align: center;
  font-size: 0.8rem;
  color: var(--text-dim);
  border-top: 1px solid var(--border-color);
}