/* =============================================
   CSS RESET & VARIABLES
   ============================================= */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --pink:       #ec4899;
  --pink-light: #fce7f3;
  --pink-dark:  #be185d;
  --blue:       #3b82f6;
  --blue-light: #dbeafe;
  --blue-dark:  #1d4ed8;
  --bg:         #fff5f9;
  --surface:    #ffffff;
  --text:       #1e1e2e;
  --muted:      #9ca3af;
  --border:     #f3e8f5;
  --radius:     16px;
  --shadow:     0 4px 24px rgba(236,72,153,.12);
  --font-display: 'Playfair Display', Georgia, serif;
  --font-body:    'DM Sans', system-ui, sans-serif;
}

/* =============================================
   BASE
   ============================================= */
html, body {
  height: 100%;
  font-family: var(--font-body);
  background: var(--bg);
  color: var(--text);
  font-size: 15px;
  line-height: 1.6;
}

/* =============================================
   SCREENS
   ============================================= */
.screen { display: none; }
.screen.active { display: flex; }

/* =============================================
   LOGIN
   ============================================= */
#login-screen {
  min-height: 100vh;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: linear-gradient(135deg, #fce7f3 0%, #dbeafe 100%);
}

.login-card {
  background: var(--surface);
  border-radius: 24px;
  padding: 48px 36px;
  width: 100%;
  max-width: 400px;
  box-shadow: 0 8px 40px rgba(236,72,153,.18);
  text-align: center;
}

.hearts-deco {
  font-size: 20px;
  color: var(--pink);
  letter-spacing: 8px;
  margin-bottom: 16px;
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% { transform: translateY(0); }
  50%       { transform: translateY(-6px); }
}

.login-title {
  font-family: var(--font-display);
  font-size: 2rem;
  color: var(--pink);
  margin-bottom: 6px;
}

.login-sub {
  color: var(--muted);
  font-size: .9rem;
  margin-bottom: 28px;
  font-style: italic;
}

.input-group {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.input-group input {
  padding: 12px 16px;
  border: 2px solid var(--border);
  border-radius: 12px;
  font-size: 1rem;
  font-family: var(--font-body);
  outline: none;
  transition: border-color .2s;
}

.input-group input:focus { border-color: var(--pink); }

#login-btn {
  padding: 13px;
  background: linear-gradient(135deg, var(--pink), var(--pink-dark));
  color: #fff;
  border: none;
  border-radius: 12px;
  font-size: 1rem;
  font-family: var(--font-body);
  font-weight: 500;
  cursor: pointer;
  transition: transform .15s, box-shadow .15s;
}

#login-btn:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(236,72,153,.35); }

.error-msg { color: #ef4444; font-size: .85rem; margin-top: 12px; min-height: 20px; }

/* =============================================
   DASHBOARD LAYOUT
   ============================================= */
#dashboard-screen {
  flex-direction: column;
  min-height: 100vh;
}

.app-header {
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  position: sticky;
  top: 0;
  z-index: 100;
  box-shadow: 0 2px 12px rgba(236,72,153,.07);
}

.header-inner {
  max-width: 500px;
  margin: 0 auto;
  padding: 14px 20px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.header-logo {
  font-family: var(--font-display);
  font-size: 1.15rem;
  color: var(--pink);
  font-style: italic;
}

.header-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

.header-greeting {
  font-size: .82rem;
  color: var(--pink);
  font-style: italic;
  font-family: var(--font-display);
}

.logout-btn {
  background: none;
  border: 1.5px solid var(--border);
  border-radius: 8px;
  padding: 6px 14px;
  font-size: .8rem;
  color: var(--muted);
  cursor: pointer;
  transition: all .2s;
}

.logout-btn:hover { border-color: var(--pink); color: var(--pink); }

.app-main {
  max-width: 500px;
  width: 100%;
  margin: 0 auto;
  padding: 20px 16px 48px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* =============================================
   CARD
   ============================================= */
.card {
  background: var(--surface);
  border-radius: var(--radius);
  padding: 22px 20px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}

.section-title {
  font-family: var(--font-display);
  font-size: 1.15rem;
  color: var(--pink-dark);
  margin-bottom: 16px;
}

/* =============================================
   MOOD TRACKER
   ============================================= */
.mood-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.mood-card {
  flex: 1;
  background: var(--bg);
  border-radius: 12px;
  padding: 16px 12px;
  text-align: center;
  border: 1.5px solid var(--border);
  transition: box-shadow .2s;
}

.mood-card:hover { box-shadow: 0 4px 16px rgba(236,72,153,.12); }

.mood-avatar {
  width: 44px; height: 44px;
  border-radius: 50%;
  display: flex; align-items: center; justify-content: center;
  font-weight: 600;
  font-size: 1.1rem;
  color: #fff;
  margin: 0 auto 8px;
}

.mood-avatar.blue { background: linear-gradient(135deg, var(--blue), var(--blue-dark)); }
.mood-avatar.pink { background: linear-gradient(135deg, var(--pink), var(--pink-dark)); }

.mood-name { font-size: .8rem; color: var(--muted); margin-bottom: 4px; }
.mood-emoji { font-size: 1.8rem; margin-bottom: 10px; line-height: 1; }

.mood-btns {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  justify-content: center;
}

.mood-btn {
  background: var(--surface);
  border: 1.5px solid var(--border);
  border-radius: 8px;
  padding: 4px 6px;
  font-size: .95rem;
  cursor: pointer;
  transition: transform .15s, border-color .15s;
}

.mood-btn:hover { transform: scale(1.15); border-color: var(--pink); }

.mood-divider {
  font-size: 1.4rem;
  color: var(--pink);
  flex-shrink: 0;
  opacity: .5;
}

/* =============================================
   MAILBOX
   ============================================= */
.tab-row {
  display: flex;
  gap: 8px;
  margin-bottom: 12px;
}

.tab-btn {
  flex: 1;
  padding: 9px;
  background: var(--bg);
  border: 1.5px solid var(--border);
  border-radius: 10px;
  font-size: .85rem;
  font-family: var(--font-body);
  cursor: pointer;
  transition: all .2s;
  color: var(--muted);
}

.tab-btn.active {
  background: linear-gradient(135deg, var(--pink), var(--pink-dark));
  color: #fff;
  border-color: transparent;
  font-weight: 500;
}

.archive-toggle-row { margin-bottom: 12px; }

.archive-toggle-btn {
  background: none;
  border: 1.5px dashed var(--border);
  border-radius: 8px;
  padding: 7px 14px;
  font-size: .8rem;
  color: var(--muted);
  cursor: pointer;
  transition: all .2s;
  font-family: var(--font-body);
}

.archive-toggle-btn:hover { border-color: var(--blue); color: var(--blue); }
.archive-toggle-btn.viewing-archive { border-color: var(--blue); color: var(--blue); background: var(--blue-light); }

/* CRITICAL: Fixed-height scrollable mail list */
.mail-list {
  height: 300px;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-right: 4px;
}

.mail-list::-webkit-scrollbar { width: 5px; }
.mail-list::-webkit-scrollbar-track { background: var(--bg); border-radius: 4px; }
.mail-list::-webkit-scrollbar-thumb { background: var(--pink); border-radius: 4px; opacity: .5; }

.letter-card {
  background: var(--bg);
  border: 1.5px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
  cursor: pointer;
  transition: all .2s;
  flex-shrink: 0;
  word-break: break-all;
}

.letter-card:hover { border-color: var(--pink); box-shadow: 0 3px 12px rgba(236,72,153,.12); transform: translateX(2px); }
.letter-card.archived { opacity: .65; border-style: dashed; }

.letter-title {
  font-weight: 500;
  font-size: .9rem;
  color: var(--text);
  margin-bottom: 3px;
}

.letter-meta {
  font-size: .75rem;
  color: var(--muted);
}

.empty-msg {
  text-align: center;
  color: var(--muted);
  font-style: italic;
  padding: 24px 0;
  font-size: .9rem;
}

/* =============================================
   WRITE FORM
   ============================================= */
.write-form { display: flex; flex-direction: column; gap: 10px; }

.form-label { font-size: .8rem; font-weight: 500; color: var(--muted); }

.form-select, .form-input, .form-textarea {
  padding: 10px 14px;
  border: 1.5px solid var(--border);
  border-radius: 10px;
  font-family: var(--font-body);
  font-size: .9rem;
  color: var(--text);
  outline: none;
  transition: border-color .2s;
  background: var(--bg);
}

.form-select:focus, .form-input:focus, .form-textarea:focus { border-color: var(--pink); }

.form-textarea {
  resize: vertical;
  min-height: 110px;
}

.send-btn {
  padding: 13px;
  background: linear-gradient(135deg, var(--pink), var(--pink-dark));
  color: #fff;
  border: none;
  border-radius: 12px;
  font-size: .95rem;
  font-family: var(--font-body);
  font-weight: 500;
  cursor: pointer;
  transition: transform .15s, box-shadow .15s;
  margin-top: 4px;
}

.send-btn:hover { transform: translateY(-2px); box-shadow: 0 6px 20px rgba(236,72,153,.35); }

/* =============================================
   LETTER MODAL — CRITICAL SCROLLING FIX
   ============================================= */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0,0,0,.45);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 16px;
  backdrop-filter: blur(4px);
}

/* CRITICAL: Fixed height + flex column = pinned header/footer, scrollable middle */
.modal-box {
  background: #ffffff;
  border-radius: 20px;
  width: 100%;
  max-width: 480px;
  height: 75vh;          /* fixed total height */
  max-height: 75vh;      /* belt-and-suspenders cap */
  min-height: 0;         /* allows flex children to shrink below content size */
  display: flex;
  flex-direction: column;
  box-shadow: 0 20px 60px rgba(0,0,0,.25);
  overflow: hidden;      /* clips anything that tries to escape */
}

/* CRITICAL: flex-shrink:0 pins the header — it will NOT shrink */
.modal-header {
  flex-shrink: 0;
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  padding: 20px 22px 16px;
  border-bottom: 1.5px solid var(--border);
  background: linear-gradient(135deg, #fce7f3, #dbeafe);
}

.modal-from {
  font-size: .75rem;
  color: var(--muted);
  margin-bottom: 3px;
  text-transform: uppercase;
  letter-spacing: .05em;
}

.modal-title {
  font-family: var(--font-display);
  font-size: 1.15rem;
  color: var(--pink-dark);
}

.modal-close-btn {
  background: rgba(255,255,255,.7);
  border: none;
  border-radius: 8px;
  width: 30px; height: 30px;
  font-size: .9rem;
  cursor: pointer;
  flex-shrink: 0;
  margin-left: 12px;
  color: var(--muted);
  transition: all .2s;
}

.modal-close-btn:hover { background: #fff; color: var(--pink); }

/* CRITICAL: flex:1 + overflow-y:scroll = this section scrolls, it doesn't push footer */
.modal-body {
  flex: 1 1 0;           /* grow AND shrink; 0 base size forces flex math to work */
  min-height: 0;         /* CRITICAL: without this, flex ignores overflow-y */
  overflow-y: scroll !important;
  -webkit-overflow-scrolling: touch;
  padding: 20px 22px;
  color: #000000;
  font-size: .9rem;
  line-height: 1.75;
  white-space: pre-wrap;
  word-break: break-all;
}

/* CRITICAL: flex-shrink:0 pins the footer — it will NOT shrink */
.modal-footer {
  flex-shrink: 0;
  display: flex;
  gap: 10px;
  padding: 14px 22px;
  border-top: 1.5px solid var(--border);
  background: var(--surface);
}

.modal-action-btn {
  flex: 1;
  padding: 11px;
  border: none;
  border-radius: 10px;
  font-size: .88rem;
  font-family: var(--font-body);
  font-weight: 500;
  cursor: pointer;
  transition: all .2s;
}

.archive-btn {
  background: var(--blue-light);
  color: var(--blue-dark);
}

.archive-btn:hover { background: var(--blue); color: #fff; }

.close-btn {
  background: var(--pink-light);
  color: var(--pink-dark);
}

.close-btn:hover { background: var(--pink); color: #fff; }

/* =============================================
   SCROLLBAR (global)
   ============================================= */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: var(--pink); border-radius: 3px; opacity: .4; }